In order to provide convenience for rehabilitation doctors to formulate rehabilitation plans for patients, this paper proposes a training method for exercise rehabilitation robots based on sensors. In this research, the customized wearable sensor and universal mobile terminal are used as the hardware. Based on the sensor, the motion capture algorithm and motion reconstruction algorithm are developed. The table of experimental results shows that the cost can be saved by using the sensor, and the data can be captured accurately, which can meet the needs of rehabilitation medicine for motor function evaluation and training guidance. The range of motion of the joint and the manual measurement value are within 5°, which can meet the needs of rehabilitation medicine for motor function evaluation and training guidance. The system delay is less than 0.5 s, which has good real-time performance and can respond quickly to emergencies, ensuring the safety of patients’ out-of-hospital rehabilitation. The training method of motion rehabilitation robot based on sensor is helpful for rehabilitation doctors to carry out statistical data of functional evaluation and is of great significance for rehabilitation doctors to make training plans for patients and carry out rehabilitation training.