The present invention discloses a supercharger-based excavation motor arm potential energy recovery and reuse energy-saving device, comprising an energy-saving device and a boom cylinder, the hydraulic system having two working ports, U1 port of the receiver cylinder and G2 port, D1 port connected to G3 port, boom cylinder piston cavity connected to G1 port; The energy-saving apparatus comprises a supercharger, an accumulator, a two-position three-way reversing valve, a normally closed solenoid valve, a normally open solenoid valve and a controller. The energy-saving apparatus of the present invention cuts into the hydraulic circuit, the corresponding solenoid valve is controlled by the controller, the supercharger that meets the required pressure change ratio is strung into the recovery oil circuit, so that the hydraulic energy of the gravity potential energy conversion during the process of excavation of the motor arm is stored in the accumulator, when the stored energy reaches the set value, the corresponding solenoid valve and proportional flow valve are controlled by the controller, and the energy stored in the accumulator is released, which is used to excavate the working condition of the motor arm lifting, to avoid the throttling loss of oil through the hydraulic valve when the boom falls.