In order to test the performance of thinwall bearing for harmonic drive reducer,a performance testing rig for thinwall bearing was designed,which is composed of mechanical part,electrical part,auxiliary part and dataacquisition part.The preliminary test of the testing rig was also carried out.The testing rig can simulate the complex working condition of thinwall bearing,such as high speed,dynamic load and longtime running.The testing rig can also online detect the parameters of thinwall bearing,such as rotating speed,load,temperature,vibration and axis center track,which provides reliable experimental conditions and data for the manufacturing and performance evaluation for thinwall bearing.