The utility model discloses an in-situ detection device for the charging and discharging volume of an electrode plate under pressure and a control system. A battery testing bin is arranged at the lower part in the rack; an actuator is fixed to the top of the rack. The actuator is connected with a pressure transmission disc through a connecting rod; a spring is arranged below the pressure transmission disc; the spring is contacted with the battery testing cabin; a pressure sensor is arranged below the battery testing bin, a moving assembly is fixed below the top of the rack, a displacement sensor is arranged on the moving assembly, a through hole is formed in the middle of the pressure transmission disc and used for allowing the displacement sensor to penetrate through the pressure transmission disc to make contact with the battery testing bin, and the moving assembly is controlled by a moving assembly driver; the actuator is controlled by an actuator driver; and finally, the microprocessor integrally controls the working pressure of the to-be-tested battery. Measuring the volume change of the electrode plate in the battery test bin through the movable test bin cathode; the device has the advantages of being accurate in measurement and convenient to use.