This series of machines adopts a new type of feeding mechanism with upper and lower feeding teeth that operate independently. By increasing the differential ratio and combining superior feeding performance, it can eliminate the misalignment phenomenon that is prone to occur during sewing. It can easily combine different fabrics together, making difficult operations such as bending and rolling edges simple and easy. Widely applicable for overlapping seams and decorative seams of various fabrics such as clothing, underwear, bedding, thin packaging, and leather products.