The vacuum loss of turbine in heat pump compressor occurred many times during the normal operation of the ethylene plant at PetroChina Liaoyang Petrochemical Company, seriously affecting the safety of the compressor unit and the operation load of the ethylene plant. Through analysis and overhaul, it was verified that there were problems such as the insufficient design capacity of jet pump and the scaling of condenser. After overhaul, these problems were solved completely, thus ensuring the efficient, safe, stable and economic operation of the compressor unit.