Nowadays, the technology of three-dimensional virtual fitting has been gradually deepened both at home and abroad. But there are few result on the setting of garment stitching, which is one of the key processes in simulation. The three-dimensional effect is produced by suturing two-dimensional garments. Accurate and convenient suture set method is one of the important steps to achieve a good simulation effect. Based on the research of current three-dimensional virtual fitting technology, this dissertation proposed a new method to set stitching information and realized the interactive suture setting process. After importing two-dimensional garment files, it can set the corresponding stitched edges through interactive steps, and save these information as files. In fitting process, the system can import these files, according which the system can apply force to the corresponding vertexes. This method can provide accurate stitching information, the garment can deform gradually under the external force and internal force, and the system can realize virtual try-on at last.