There is a phenomenon of energy loss in the process of boom descending of hydraulic excavator. In order to solve this problem, an oil-liquid hybrid energy recovery and reuse system was proposed,in which a continuous supercharger was used to match the pressure between the accumulator and the boom cylinder in the process of energy storage and release.The basic principle of continuous supercharger was introduced.The mathematical model of the energy recovery system was established and its simulation model was established based on AMESim.The results show that the system can effectively recover the potential energy lost in the descending process of the boom and store it in the accumulator;under the condition of constant load, energy recovered for every three boom drops will be able to jack up the boom again. By calculation, the energy recovered by the system accounts for about 47% of the recoverable energy.