Provided is a double-acting-force blow-down valve. The double-acting-force blow-down valve comprises a valve body, a valve deck and a support which are connected in a matched mode, a valve rod is movably connected in the valve body, the valve deck and the support, a bevel gear is connected to the end, arranged on the support, of the valve rod, two gate plates are connected to the end, arranged on the valve body, of the valve rod, and the valve body is internally provided with an inlet end valve seat and an outlet end valve seat which are matched with the two gate plates for use; a limiting part which penetrates into the valve body is arranged outside the valve body. The double-acting-force blow-down valve is reasonable in structure and convenient to use, the integral type valve body is adopted to replace the split-type design, the valve is more compact in structure and light in weight, leakage points outside the valve are reduced, the semi-circular design is adopted by the outlet end valve seat of the valve body, the contact area of the first gate plate and the outlet end valve seat when the first gate plate is closed is decreased, and the goodness of fit of the inlet sealing face can be better guaranteed; meanwhile, the friction force of a medium acting on the gate plates when the gate plates are opened and closed is reduced, the matching requirements between the valve body and the valve seats and between the valve seats and the gate plates are met, it is guaranteed that an inner cavity of the valve body is smooth, free of dead angle and smooth in slagging, and the double-acting-force blow-down valve is worthy of popularization.