The invention discloses an auxiliary workbench for replacing a pressure accumulator of a submarine cable oil pump station system. The auxiliary workbench comprises a base, a main frame, a scissor jack, a lifting seat, a rotating seat, supporting arms, a driving motor and hoop assemblies, wherein foot wheels is arranged at the bottom of the base, the main frame is in a rectangular shape and is vertically fixed on the front side of the base, the two opposite side walls of the main frame are provided with guide rails, the lifting seat is arranged between the guide rails, the scissor jack is installed on the base, the movable end of the scissor jack is connected with the bottom of the lifting seat, the rotating seat is rotationally installed in a round hole in the center of the lifting seat, the two supporting arms face the front side of the base, the rear ends of the supporting arms are fixedly arranged on the rotating seat at intervals, the front ends of the supporting arms are connectedwith the hoop assemblies correspondingly, and the driving motor is arranged behind the lifting seat and is used for driving the rotating seat to rotate and can move up and down along with the liftingseat. According to the auxiliary workbench, the replacement operation risk of the pressure accumulator can be reduced, and the replacement efficiency of the pressure accumulator is improved.