The invention discloses a hot extrusion molding method for a pipe nozzle of a main steam super pipeline, which relates to a hot extrusion molding method for utilizing a whole set of dedicated molding die to forge the pipe nozzle of the nuclear power main steam super pipeline. A steel pipe blank is mechanically processed into a main pipe blank with qualified dimension. A preset hole is arranged according to the position of the pipe nozzle of the super pipeline. The operation of positioning the three centers of a punch, the preset hole and a female die is completed by utilizing the female die and a supporting positioning pin. The position, i.e. the peripheral region of the preset hole which needs to be extruded, is heated. An inverted extrusion pressure is applied from the inside of the pipe blank to outside to make a parent metal of the steel pipe blank plastically deformed outward and molded into the pipe nozzle with the required dimension. Compared with the conventional welding method, the method not only can realize connection between the pipe nozzle and the female pipe, does not cut off the fibers of the steel female pipe and the pipe nozzle, but also does not need to weld, realizes the integrated molding of the super pipeline and the pipe nozzle, improves the internal quality of the super pipeline and achieves the requirements of the design party for the product.