Abstract: A high performance floss silk was prepared by means of combination treatments of lye,extra high temperature and softener prepared by researchers themselves.Concentrations of lye and softener,treating time under extra high temperature and treating time with softener were used as factors in orthogonal experiments and the data were analyzed by DPS.And it was found that these factors have no significant influence on the elastic recovery percentage of the floss silk,whereas the softener has significant influence on its compression ratio and oil content.The elastic recovery percentage of the treated floss silk is 92.37%～97.66% and the compression ratio,59.21%～66.77%,both are superior to the criteria set by the textile industry for the superfine wadding floss silk.Its oil content is 0.28%～1.39%.The average warmth retention rate is 81.91%～85.24% and average thermal transmittance coefficient,21.37～(27.13 W/(m~2·℃).) Treatment with extra high temperature steam is beneficial to the elasticity and loftiness of floss silk.Suitable processing techniques for floss silk are given.