Drain cover mold forming principle of drain cover mold, raw materials are generally ditch mold of plastic injection molding and mold steel plate two, trench cover die box using polypropylene plastic injection molding machine after high temperature treatment into the granular channel prepared a cover plate cavity, stay after cooling treatment after forming a trench cover die box; trench cover steel mold with 3-8 mm plate after cutting, crimp, shape, reinforcement, welding, assembly, polishing and other multi-channel formalities made