According to the detail working conditions of multi rope friction winders,the authors analyzed the contacting pattern between rope and liner and the effects of actual contacting area on friction drive,and had knowledge of the relative regularities between the relative sliding velocity,specific pressure and the friction coefficient.Meanwhile,they modified the traditional Euler's formula and obtained the friction drive equation for multi rope friction winders.The results are of certain theoretical value to the sliding proof reliability design of multi rope friction winders.