Valve safety cut-off device suitable for gas storage vehicle

The valve safety cut-off device comprises the gas storage vehicle and a gas storage tank fixed to the upper portion of the gas storage vehicle, a pipe opening used for inputting or outputting gas is formed in the rear side of the gas storage tank, a valve used for controlling opening and closing of the pipe opening is arranged on the pipe opening, and a pull rod used for pulling the valve to move longitudinally to achieve opening and closing of the valve is fixed to the valve. The upper end of the pull rod is connected with a cross rod, the outer portion of the air storage tank is covered with a fire-fighting cabinet, the inner side end of the cross rod is hinged to the inner side of the fire-fighting cabinet, the middle of the cross rod is hinged to the pull rod, and the upper portion of the outer side of the cross rod is connected with the fire-fighting cabinet through a contraction spring to guarantee that the pull rod is lifted upwards to seal the pipe opening under elastic pulling of the contraction spri