This model adopts a linkage type feeding structure, which has good durability and balanced feeding. It can achieve consistent feeding of upper and lower layers during the sewing process for bulky sewing materials and medium thick sewing materials with high mobility. Using built-in integrated computer control technology, with stable performance and strong anti-interference ability. Adopting a new type of curved needle to form a single line chain stitch without changing the bottom line, improving work efficiency: adopting a fully automatic lubrication device to extend the service life of the machine. It has multiple intelligent sewing modes such as automatic needle positioning, automatic needle counting, automatic thread cutting, electronic thread clamping, automatic lifting and pressing foot, and lifting and dragging cloth wheel device. Suitable for sewing medium thick materials, bags, leather jackets, leather products, sofas, etc.