Three-thread sewing machine is one of the most widely used sewing machines in the market at present, which is mainly used for edge treatment of fabrics. Has the characteristics of good therapeutic effect and high speed. Three-thread sewing machine uses three threads to sew, two of which form a plane sewing effect, and the third thread is used to reinforce and prevent the thread ends from spreading. This method of edge locking can effectively prevent the fabric edge from cracking and coming off the thread, and make the edge more firm and beautiful. The working speed of the three-line sewing machine is faster, which can efficiently complete a large number of production tasks and improve production efficiency. Whether it is a clothing factory, a shoe factory or other textile products manufacturing enterprises, the third-line sewing machine is one of the first choice equipment.