The utility model relates to an automobile-used special gas cylinder valve, particularly relates to an automobile-used gas cylinder opening and closing device and aims to provide a gas cylinder valve suitable for being filled with special gas. The automobile-used special gas cylinder valve comprises a valve body, a pressing cap, a valve rod, a valve, a seal ring, a handwheel, a spring and a spring pressing cap; the valve and the valve rod are mounted in the valve body; the valve is embedded with the inner end of the valve rod; a sleeve gasket, the handwheel and the spring are arranged at the outer end of the valve rod in sequence; the spring pressing cap is fixed at the outer end of the valve rod; a valve body pressing cap is in threaded connection with the valve body; tapered threads connected with the gas cylinder are formed at the lower part of the valve body; an adaptor of a channel on one side of the valve body is connected with user equipment, a safety relief device is mounted in the channel on the other side of the valve body; and a safety pressing cap is assembled in a pressure release hole of a pressure release channel. The automobile-used special gas cylinder valve is characterized in that a polytetrafluoetylene taper seal ring is mounted in the valve body pressing cap and the valve body pressing cap is press-coated with an aluminum sheet flat washer and sealed with the valve body; the flat washer is sleeved on the excircle of the valve rod; fusible alloy filling material is casted in the relief hole of the safety pressing cap; and an safety film is installed at the inner end of the safety pressing cap. The utility model is suitable for the automobile-used special gas cylinder valve.