The utility model provides an arc zip fastener convenient to sew up fixedly, including the chain belt, the chain belt includes outer arc chain belt and inner arc chain belt, and the inward flange of outer arc chain belt is equipped with outer sprocket, and the inward flange of inner arc chain belt is equipped with interior sprocket, and the space width of outer sprocket is greater than the space width of interior sprocket, and outer arc chain belt and inner arc chain belt are the cloth chain belt, and the outward flange of outer arc chain belt and the outward flange of inner arc chain belt allare equipped with and cut the mouth, cut out the notched orientation that cuts towards the chain belt inward flange. Outward flange through outward flange at the outer arc chain belt and inner arc chain belt all is equipped with and cuts the mouth, and cuts out the notched orientation that cuts towards the chain belt inward flange, and during the arc of sewing up the zip fastener clothing like this department, the accessible is cut out notched deformation and so that the chain belt can shrink naturally, is made things convenient for sewing up of zip fastener fixed, and the chain belt of the department of sewing up does not have obvious wave fold to the pleasing to the eye degree of assurance zip fastener, and the intensity of chain belt is reliable, durable, difficult damaged.