The fire-resistant plug cover is provided with a plurality of elastic snap-fit members on one side, and the bottom end of the elastic snap-fit members away from the fire-resistant plug cover is elastically deviated in a direction away from the center axis of the fire-resistant plug cover for snap-fit mounting of the bottom end of the elastic snap-fit members with the floor of the automobile after passing through the floor holes.

It can extend into the floor hole after a certain elastic deformation and realize snap-fit mounting after elastic reset, so that the plate surface of the fire-resistant plug cover is tightly attached to the automobile floor to form a certain sealing effect.

The hot melt sealing body, which is disposed on the outside of the plurality of elastic snap joints, is disposed at the periphery of the bottom surface of the fire-resistant plug cover and is sealingly connected with the fire-resistant plug cover, and the inner edge thereof is pressed against the elastic snap joints.

In the subsequent automobile painting and baking processing step, the bottom surface of the hot melt sealing body will be partially melted, and the automobile floor sheet metal parts for bonding and fixing, to ensure that the other side of the automobile floor smoke can not be entered into the car body through the floor holes.