The invention discloses a precision-loaded RV reducer performance detection device and method, including a test bench and a measurement and control system; wherein, the test bench includes a bench, a tested RV reducer bracket, a power end sliding platform, and a power end sliding platform track , load-side sliding platform, load-side sliding platform track, power motor, load motor, tested RV reducer, accompanying test RV reducer and other components; the measurement and control system includes hardware and software parts, and the hardware part mainly includes industrial computers and sports cards. , Data acquisition card, input torque speed sensor, output torque speed sensor, input grating, output grating, vibration acceleration sensor, etc. The software part mainly includes speed fuzzy PID control program, torque fuzzy PID control program, torque speed fuzzy PID control program, etc. The invention ensures high coaxiality when the components are installed, thereby effectively improving the stability and reliability of the performance detection of the RV reducer.