Abstract: Towel rapier loom GA799-Ⅰ changes weft density by intermittent take-up formed from separation and association of electromagnetic clutch.But the defects of GA799-Ⅰ are such that the length of satin section and the weft density are not coincident with the design parameters.By using chain driving and gear driving, the design solves the technical problem,and changes the design of the length of satin section from 30～(50 mm) to 300～(500 mm.) This design provides a theoretical basis for those enterprises manufacturing products of the same kind.