Aiming at the low ratio of load and deadweight for traditional humanoid manipulators,a humanoid robot arm with a multi-motor coupling drive mode was proposed.According to the motion characteristics of the human arm,the configuration of the humanoid robot arm with series structure was determined,and the robot arm was divided into the shoulder joint module,the elbow joint module,and the wrist joint module.The rope transmission characteristics of a single motor driving a single joint model were analyzed,and the torque mapping relationship and rotation angle mapping relationship between motor and joint of the model were derived.Moreover,the motor layout and winding mode of multi-motor coupling driving multi-joint were studied in each module,and the working principle of multi-motor coupling was explained.Meanwhile,the torque mapping relationship and rotation angle mapping relationship between motor and joint in each module were deduced.The correctness of the mapping relationship in each module and the bearing capacity of each module joints were verified by experiments.The results show that the multi-motor coupling driving mode can effectively improve the bearing capacity of each joint on the premise of ensuring weight,it also provides a theoretical basis for the design of a humanoid robot arm.