Working arm and tunneling trolley

The utility model relates to a working arm which comprises a movable arm, a bucket rod arm, a connecting base, a small arm, a breaking hammer, a rotary support and a deflection oil cylinder. The head end of the movable arm is hinged with a frame of the tunneling trolley; the tail end of the movable arm is hinged with the head end of the bucket rod arm; the tail end of the bucket rod arm is hinged with the connecting base; the rotary support is arranged on the connecting base; the rotary support is connected with the head end of the small arm; the tail end of the small arm is hinged with the breaking hammer; one end of the deflection oil cylinder is rotationally connected with the small arm; the other end of the deflection oil cylinder is rotationally connected with the breaking hammer; the small arm can drive the breaking hammer to rotate when rotating; the deflection oil cylinder can adjust the deflection angle of the breaking hammer so as to compensate the rotation angle of a frame of the tunneling trolley,