The metal seal plunger gate valve adopts the national standard gate valve size design of the non-metallic seal flange to connect the waist drum plunger gate valve and the metal seal flange to connect the waist drum plunger gate valve of the handwheel operation mechanism has two forms, one is shown in Figure 6 and Figure 8, and the other new form is shown in Figure 7, that is, the handwheel only rotates without doing up and down movement and the valve stem only does up and down movement without rotating. When the valve is fully open, the stem extends to the highest point, but still inside the protective sleeve.