Balanced filling valve for dock and mounting method

The invention relates to the field of dry dock construction, and discloses a balance filling valve for a dock and an installation method.The balance filling valve comprises an embedded frame embedded around an opening in the top of a filling valve cavity and further comprises a cover plate; the top of the valve body is sealed through a top cover, and a vertical through hole is formed in the middle of the top cover; the top of the vertical support is connected with the cover plate, and the bottom of the vertical support penetrates through the vertical through hole and then is connected to a valve body middle platform located in the cylindrical valve body. The hydraulic oil cylinder is arranged on the middle platform of the valve body; the piston end of the hydraulic oil cylinder extends into the vertical through hole and is fixedly connected with the top cover; the guide ring is arranged below the cylindrical valve body and located at the bottom of the filling valve cavity, the water inlet is formed in the sid