On the basis of the multi-segment function construction method, the reproduction design of non-circular gear pairs with preset time-varying transmission ratio has been proposed. Combined with the practical application of non-circular gear pairs in industry, a continuously variable transmission mechanism with non-circular gear pair has been presented. The influence of basic parameters of non-circular gear with output transmission ratio is discussed. Based on SolidWorks 、Adams and other software, the simulation model of this continuously variable transmission mechanism is established. The output characteristics are verified by the simulated motion in ADAMS.