The slippage between discs and rail is one of important factors for the measurement accuracy of an involute. However,control of frictions effectively can modify the slippage of discs.In the paper, frictions between discs and rail are analyzed respectively when a cord and a belt are used to drive the discs to roll. According to the analysis and experiment,it shows that if measuring forces are 0.7 N and 0.2 N and the base discs is drived by the cord and belt, frictions are 0.02 N and 0.07 N respectively, for the base disc clockwise rolled; where the effect of the slippages of based discs on the involute measurement can be ignored. Moreover, the slippage can also be reduced by increasing the weight of base disc groups, and measurement difference of involute is 0.06 μm when the rolling directions of the base discs are different.