High precision welding method for rudder horn, propeller shaft bracket and intermediate shaft bracket of long shaft ship

The invention discloses a high precision welding method for a rudder horn, a propeller shaft bracket and an intermediate shaft bracket of a long shaft ship, belonging to the field of ship welding. In the high precision welding method, a shaft center line of the ship is firstly pulled out according to design requirements when the ship is assembled and installed; after the shaft center line is examined, the following three steps are synchronously carried out: firstly, welding of the rudder horn; secondly, the welding of the propeller shaft bracket; and thirdly, the welding of the intermediate shaft bracket. Compared with the prior art, because installation phases of the propeller shaft bracket and the intermediate shaft bracket are advanced to the assembling phase, the construction condition is improved, and the installation precision is ensured; and because the complete cross section of a ship body is horizontally assembled (the complete cross section is the propeller shaft bracket which is reversely placed, and the intermediate shaft bracket is over the intermediate shaft bracket), the installation position can be adjusted by fully utilizing a crane when the ship body is installed, the working efficiency is improved, and the utilization time of a dock is greatly reduced.