The utility model relates to an infusion alarm gas-cutting valve used for coal gas and other gas device for exercising reliable cutting of replaceable metal-sealing ring. The utility model comprises a valve body, a screw rod arranged inside the valve body, a cuniform block positioned under the screw rod and a flashboard arranged outside of the cuniform block. When gas-cutting valve is turned on, the overhaul window opened on the shell of the corresponding flashboard is provided with an open-close sealing overall window cover. The utility model is characterized in that: on the corresponding valve sealing place outside the flashboard is provided with a metal sealing loop via a bolt. On the metal sealing loop, the valve sealing places as well as the contact place between the metal sealing loop and flashboard are provided with a rubber sealing loop. The utility model has the advantages of saving time, power and money as well as being reliable and secure.