Such machinery feature stable machine molding and large operating space. The adoption of the connecting bar thread-taking-up, rotating hook thread-hooking and drop feeding can form the lockstitches. The trimming can be finished during the sewing. Stitches are stable and trimming is tidy. Cutting devices for different cloth specifications are available. They are applicable to the sewing of garment pieces for the top-grade shirts and suits, especially the sewing of the garment pieces for the collars and flaps.