In order to test the transmission performance of the three-pulley noncircular synchronous belt transmission mechanism and obtain its transmission accuracy, a three-pulley noncircular synchronous belt transmission performance test bench was designed and tested. The three-pulley noncircular synchronous belt transmission test bench was mainly controlled by an industrial computer and stepper motors. It can realize the functions of adjustable speed, load and center distance, real-time display, collection, statistics and analysis of test data. Two indexes of transmission cycle deviation rate and transmission ratio accuracy deviation rate were defined, which were used to measure the transmission performance of the three-pulley noncircular synchronous belt. It was found through experiments that the test bench can realize three-pulley noncircular synchronous belt transmission test under different working conditions, and the size of load and speed affected the transmission ratio accuracy deviation rate and transmission cycle deviation rate, and had more influence on the transmission cycle deviation rate. When the speed was in the range of 0~300r/min and the torque was in the range of 0~50N·m, the test drive-driven wheel transmission ratio was basically consistent with the theoretical drive ratio;the drive-driven wheel transmission cycle deviation rate was 0.80%~4.80%. The accuracy deviation rate of the driving ratio between the main and driven wheels was between 0.18% and 1.23%;when the speed was 80r/min and the load torque was 16.25N·m, the accuracy deviation rate of the transmission ratio was 0.18%, and the transmission cycle deviation rate was 0.80%, which was the best transmission condition within the test range.