The invention relates to a manufacture method of ultra-large-diameter pipeline extruded nozzles. The method comprises the following steps of: straightening and finishing a stainless steel tube blank, so as to ensure that the straightness and the size of the stainless steel tube blank is uniform, rapidly heating the treated stainless steel tube blank through an induction coil, so as to ensure that the temperature of the stainless steel tube blank reaches 1,150 to 1,200 DEG C, preheating a die, keeping the preheating temperature at 100 to 200 DEG C, conveying the heated stainless steel tube blank into the die, ensuring that the temperature of the stainless steel tube blank is more than 1,100 DEG C, inserting a core rod into the stainless steel tube blank, applying force to the guide section side of the core rod from the extrusion side of the core rod, and performing one-way extrusion, so as to ensure that steel is filled in die holes of the die and to extrude a nozzle shape. By adopting the method, not only can nozzles be produced in ultra-large-diameter stainless steel pipelines, but also the nozzles have good physical properties, material is also saved, and the operability is high.