Abstract: Aiming at the problem of high temperature of bearing insert in large oil pump unit, various technologies such as using Freon refrigeration, PLC temperature control and superconducting heat pipe are put forward and a kind of applied Freon refrigeration cooling system is designed and developed.Practical application result indicates that the system can cool the high temperature of bearing insert in large oil pump and motor efficiently, which cuts down the fault rate caused by shutting down of oil pump units and economizes maintenance cost.