Based on the EH oil pump current abnormal phenomenona of EH system such as sharp change with oil flow dramatic change in the process of the start-up commissioning, the reasons of oil pressure anomaly were examined by combining with the structural characteristics of EH system, the operating principles of the hydraulic system and the valve control principle, and the cumulative experiences of commissioning for many years. And the countermeasures were proposed by analyzing the dynamic process and oil pressure abnormal phenomenona of the EH system. It provides reference to the commissioning and operation of the same type of EH system.