The use of a multi-functional excavator for complex pipeline construction brings great convenience to pipeline engineering. During excavation and drilling operations, the gravitational potential energy of the boom is converted into hydraulic energy and flows back to the oil tank at the overflow valve to form overflow loss. A flow regeneration loop was set in the hydraulic oil circuit of the boom to improve the action rate. The valve control system was used to recover the gravity hydraulic potential energy dropped by the boom, and the quantitative motor was driven by the hydraulic energy recovered in the accumulator to motivate the generator to generate electricity. The electric energy was stored in the battery to provide electric energy for other electrical appliances of the excavator. Using AMESim software for hydraulic simulation, compared with existing excavators, recovering the hydraulic energy of the boom descent greatly improves the energy utilization rate of the system, and the flow regeneration improves the movement speed of the excavator. The research results show that the energy recovery efficiency of boom descent is about 40%.