The cryogenic stop valve uses a special sealing structure (such as flexible graphite, PTFE) to prevent leakage, and uses stainless steel, cryogenic steel and other materials to deal with condensed water and corrosive environments. This valve is widely used in various ultra-low temperature media control occasions to ensure system sealing safety and reliable operation. It is one of the key valves that are indispensable for cryogenic engineering.