Provided is a finishing treatment method of seamless sportswear and outdoor clothing, including: welding two or more moisture-permeable waterproof fabrics with an ultrasonic welder in a state of overlapping end parts thereof each other; and finishing the end parts of the moisture-permeable waterproof fabrics with a seal sealing tape, whereby in the seamless sportswear and outdoor clothing which are finishing treated according to the embodiments of the present invention, since a sewing part such as over lock and the like is removed, a friction or compression phenomenon can be prevented from being generated from a part to which a pressure is applied, a sewing wrinkle generation phenomenon generated upon sewing and a coating face slip phenomenon of the moisture-permeable waterproof fabric due to a sewing needle can be solved, and excellent tensile strength and waterproof performance can be realized.