Abstract: The ultrafine denier cotton-feeling nylon down fabric was weaved by fine denier fully matt nylon FDY 20 D/24 f in the warp and ultrafine denier fully matt nylon FDY 20 D/68 f in the weft. Based on the research and optimization of the weaving, and dyeing and finishing process, the study develops a new kind of ultrafine denier nylon down fabric. By testing and comparing it with fine denier polyester down fabrics with similar specifications, the application advantages of ultrafine denier nylon in the development of down fabric were verified.