For polynomial function method is simple and easy to understand, it is widely used in designing cam curves.However,when in the design of high speed cam, it is often required that the cam curve can realize high order and be continuous, then the number of polynomials should be increased to realize the design requirements. It no doubt increases the difficulty and reduces the precision of procession, eventually leads to the cam corresponding movement rule cannot be realized. In view of the above, a polynomial curve design method of the 7, 9 and 11 powers variable coefficient. Then by calculating the cam curve equation and characteristic parameters, drawing the characteristic parameters, the effects of changing the kinematics and kinetic characteristics of cam curve was achieved, and improving the flexibility and selectivity of cam curve design was improved.