Abstract: Friction drive is mainly a mechanical transmission mode which realizes power transmission by friction between belt and pulley，pulley and pulley.Friction drive has be used especially and typically in field of walking machinery.According to friction drive examples of automatic speed regulation car，combine harvester，aircraft tractor and road-railer，function and usage method of friction drive used in walking machinery were explained，principle of belt-pulley friction to fulfill continuous variable ratio drive and structure of stepless speed regulating device were revealed，and usage methods of pulley-pulley friction drive used in walking machinery were expounded.