The present invention relates to a method for manufacturing an integrated catheter balloon which has improved quality and prevents separation caused by water leakage and clogging of an expansion line by improving a molding method of a balloon inlet, and in which a first tube is supplied to a second tube to be continuously molded at predetermined intervals when molding the first and second tubes by a second extrusion so as to allow a cutting part to be formed between the first tubes, thereby promoting a simplification of a manufacturing process and improvement of productivity. According to the present invention, a method for manufacturing an integrated catheter balloon comprises: a first tube molding step of molding the first tube of an outer diameter predetermined by first extrusion in order to form a discharge line and an expansion line, and then cutting off the same in the predetermined length by curing； a balloon inlet puncturing step of puncturing the balloon inlet to allow liquid to be introduced to an area to be expanded after inserting a support rod into the expansion line； a releasing agent coating step of setting a section on an outer periphery surface around the balloon inlet, applying and drying the releasing agent, and detaching the balloon inlet from a below-described second tube to be expanded to the balloon； a second tube molding step of secondly-extruding to integrally mold the second tube having the uniform thickness in the length direction on an external part of the first tube by supplying the first tube to a forming mold of the second tube at the predetermined intervals, and at the same time, forming a cut-off part on the second tube positioned between the first tubes having the predetermined intervals.
