The performance testing system of internal combustion engine cooling water pump was designed. The hardware composition, software design and testing contents of the performance testing system were introduced. For the system, the trinity of IPC, HMI and PLC, and highly effective and cooperative control concept were adopted; PD, fuzzy PID and other classical control algorithm were used to control the temperature, flow, speed and other physical quantities. The testing software was developed by using LabVIEW. The system has the functions of detecting the performance, cavitation, sealing and reliability of internal combustion engine cooling water pump, and can automatically carry out the performance curve fitting, report generation. The automatic detection is realized.