According to data from MIR DATABANK, approximately 50 fully formed humanoid robots were sold in China in 2023, a figure so small it is almost negligible, resembling more like a one-off product display in a laboratory. However, by 2025, this number surged to about 15,000 units. The leap from 50 to 15,000 units is not merely a simple numerical change, but a clear industrial signal: humanoid robots are stepping out of the laboratory and entering the stage of true mass production.
Once mass production scales up, demand for upstream core components will surge first. In humanoid robots, one of the most critical components is the reducer within the joints.
1. Humanoid Robot Reducers: 430,000 Units Is Just the Starting Point
In simple terms, the function of a reducer is to convert the high-speed rotation of a motor into the low-speed, high-torque output required by the joints—without it, the robot would struggle to even raise its arms or take a step.
In 2025, a standard humanoid robot is equipped with more than 14 reducers. These reducers are distributed across various joints, including the shoulders, elbows, wrists, hips, knees, and ankles, forming the physical foundation for the robot's movement.
According to data from MIR DATABANK, the overall sales volume of third-party reducers in China's humanoid robot sector reached approximately 430,000 units/sets in 2025. Looking ahead, as humanoid robots achieve commercial deployment and sales of high-degree-of-freedom models increase, reducer sales will also continue to grow at a high rate.
2. Harmonic Reducers for Upper Limbs, Planetary for Lower Limbs, and Cycloidal Still Awaiting Its Opportunity
The current mainstream solution in the humanoid robot field is a combination of "harmonic reducers + planetary reducers." Harmonic reducers are compact, lightweight, and highly precise, primarily used in upper limb joints such as arms and wrists that require fine movements; planetary reducers feature a simple structure, high rigidity, and strong shock resistance, making them more suitable for lower limb joints that bear heavy loads.
The core reason this combination has become mainstream is its maturity. Harmonic and planetary reducers have been used in the industrial robot field for many years, featuring stable supply chains, controllable costs, and performance that perfectly fits the current demand range of humanoid robots—not perfect, but sufficient.
In the harmonic reducer field, traditional harmonic manufacturers such as Leaderdrive, Laifual Drive, Leaderdrive, and Tongchuan Technology currently dominate. The market concentration is high, and customers have stringent requirements for technical strength and customization capabilities. However, a noticeable change in 2025 is that new players are entering the market—companies like Zhongda Leaderdrive, Siling Intelligent Drive, and Zhongding Co., Ltd., which originally manufactured planetary reducers, machine tool components, or automotive parts, are now pivoting to the harmonic track.
Image source: Public financial reports
The situation in the planetary reducer field is similar, with Zhongda Leaderdrive and Newstart combined holding over 70% of the market share, mainly supplying top humanoid robot companies like Agibot and Unitree. RV reducer manufacturer Huandong Technology, along with automotive parts manufacturer Fuda Co., Ltd., also announced their layout in planetary reducers in 2025.
Another player is slowly emerging: the cycloidal reducer. It can handle larger loads than harmonic reducers and offers higher precision than planetary reducers, theoretically making it more suitable for scenarios like humanoid robots that require both flexibility and load-bearing capacity. The issue is that the manufacturing process for cycloidal reducers is complex, costs are high, and torque density still needs optimization. Currently, it is still in the small-batch validation stage, with representative manufacturers including Dongyi Technology, Kemeng Innovation, Huandong Technology, and Guomao Shares.
However, many in the industry are optimistic about its future. As humanoid robots transition from exhibitions to actual labor operations, the load and lifespan requirements for joints will significantly increase, and that is when the advantages of cycloidal reducers will become prominent.
3. Three Trends Are Reshaping the Industry
Looking back from the end of 2025, the humanoid robot reducer industry is transitioning from the initial stage to the growth stage, and there are three trends worthy of continuous attention.
The first is the continuous iteration of transmission solutions. The "harmonic + planetary" combination is the current pragmatic choice, but if cycloidal reducers can solve their process and cost issues in the next few years, they are highly likely to become the standard configuration for the next generation of high-performance humanoid robots.
The second is the continuous change in the competitive landscape. Precision transmission manufacturers, automotive parts enterprises, machine tool parts companies, and other types of players are now competing fiercely in the same track. Over the next three to five years, this industry will most likely undergo a round of consolidation, where technical accumulation and customer relationships will determine who wins in the end.
The third is the positive cycle between technology and scenarios. This is not a one-way story of "technology driving applications"—more advanced reducers enable robots to complete more complex tasks, while richer application scenarios, in turn, impose higher requirements on the lifespan, precision, and cost of reducers. This mutually reinforcing cycle is the true engine for the continuous evolution of this industry.
Behind these three trends, they actually all point to the same core proposition: supply chain capabilities will determine the ceiling for the mass production of humanoid robots. Reducers are just one part of it; core components such as joint modules and force sensors are also facing the test of moving from technological breakthroughs to scaled delivery. To systematically sort out these issues, we will hold the Online Seminar on In-depth Analysis of Emerging Markets in the Second Half of 2026 on the MIR DATABANK Video Channel on August 5. Chen Ningxin, Chief Analyst of the Robot Business Division at MIR DATABANK, will deliver a keynote speech titled "Tackling the Core Supply Chain of Humanoid Robots Amid the Mass Production Wave." We will focus on upstream core components such as joint modules, reducers, and force sensors, interpret industrial demand and value, focus on the direction of technological breakthroughs, and reveal how component technology iteration and manufacturing provide solid underlying support for the mass production of humanoid robots. Welcome to reserve your seat!