Abstract: This article takes the comprehensive HPU used in petroleum automated drilling rigs as the object of discussion. The causes of HPU oil leakage are analyzed from the aspects of hydraulic oil pollution, abnormal temperature of hydraulic oil, hydraulic oil tank structure design, and pipeline impact vibration. A comprehensive improvement plan is proposed for the design of hydraulic oil cleanliness and temperature abnormalities, hydraulic oil tank structure optimization design, and pipeline vibration and pressure impact design. Through case verification, the improvement measures can significantly reduce the risk of leakage, extend the service life of hydraulic systems, and have important reference value for the design of HPU and even hydraulic systems.