The invention discloses a mining mechanical crushing device. The mining mechanical crushing device comprises a supporting bottom plate. The upper portion of the supporting bottom plate is fixedly connected with a supporting frame. The upper portion of the supporting frame is fixedly connected with a fixing plate. An air cylinder is arranged in the supporting frame. A motor is arranged on the air cylinder, and one end of the motor is connected with an air valve. The upper portion of the air cylinder is connected with an air pipe through the air valve. A hollow slideway is connected with one side of the fixing plate. The upper portion of the hollow slideway is connected with a supporting pillar. An electric telescopic rod is arranged under the supporting pillar. The lower portion of the electric telescopic rod is fixedly connected with an impact cylinder. The impact cylinder is provided with a sliding block at the hollow slideway. An impact rod is arranged in the impact cylinder, and one end of the impact rod is connected with a tool bit. The supporting pillar is provided with a round hole, and the air pipe penetrates through the round hole in the supporting pillar to communicate with the impact cylinder. The mining mechanical crushing device is reasonable in design, is wide in application range, greatly relieves burdens on workers, and is worth vigorous popularization.