Non-flexible adjustable one-piece underwear

The present invention utilizes special cutting means and sewing effect of threads to form a low breast sewing line, a front vertical sewing line, a back vertical sewing line, a front horizontal sewing line and a back horizontal sewing line. The low breast sewing line can enhance the three-dimensional effect to the breast of the wearer. The front vertical sewing line is able to make the curve of the abdomen and waist flatter to embellish the curve of the wearer. The back horizontal sewing line, located at a position where the back contacts waist, is resonant with ergonomics to avoid cloth deposition at the back and waist of the wearer. The back vertical sewing line at the bottom provides the effect of raising bottom and thus increases the three-dimensional effect for the bottom. Accordingly, it is able to form a whole one-piece underwear with the effect of embellishing body figure and adjusting body shape.