After the shutdown of the ethylene plant at PetroChina Dushanzi Petrochemical Company for maintenance, the radial bearing bush temperature at the turbine side of propylene refrigeration compressor kept rising during operation. The causes of the rise of bearing bush temperature were investigated, and API Group V base oil was injected into the propylene refrigeration compressor in advance to solve the problem of radial bearing bush temperature rise at the turbine side according to the previous experience, thus ensuring the long-term operation of compressor unit.