Hydraulic pliers refer to professional hydraulic tools specifically used for crimping cables and wiring terminals in power engineering. There are integrated, split, electric, manual, etc. Hydraulic pliers are divided into several categories: separate/integral cable hydraulic pliers, mechanical cable wiring pliers, steel core cable hydraulic pliers, manual hydraulic pliers, electric hydraulic pliers, and so on. The hydraulic clamp is composed of an oil tank, a power mechanism, a directional valve, a pressure relief valve, and a pump oil mechanism. The pump oil mechanism is composed of an oil pump body, high and low pressure oil outlet holes, an eccentric shaft, an eccentric bearing, a driven gear, a pair of high-pressure oil pumps, and a low-pressure oil pump. The oil pump body is suspended on the oil tank cover, and the high and low pressure oil outlet holes are opened on the oil pump body and connected to the pressure relief valve oil circuit. The eccentric shaft is longitudinally arranged, and the upper end is pivoted in the center of the oil pump body, The lower end is fixed with an eccentric bearing, and the driven gear is fixed on the top of the eccentric shaft, connected to the power mechanism. The high and low pressure oil pumps are suspended on the oil pump body, each with an actuator in contact with the eccentric bearing. The pump cavities of the high and low pressure oil pumps are respectively connected to the high and low pressure oil outlet holes. The connection between the pump oil mechanism and the power mechanism is vertical, which can fully utilize space and reduce the occupied area, which is beneficial for operation and transportation; Transforming the pump oil form of high and low pressure oil pumps into the action form of eccentric bearings has the advantages of simple structure, fewer components, and easy assembly