In view of the narrow range and small maximum transmission ratio of the existing Continuously Variable Transmission（CVT），this paper proposes a CVT driven by cam mechanism. The CVT adjusts the position of the intermediate lever fulcrum by the shifting device and changes the force arm to adjust the rotational speed of the follower and achieve the aim of stepless shifting. According to the change rule of the speed in the output end of the rocker arm，the speed of the swing arm is controlled to change according to a certain rule, and the output speed is compensated reversely，which improves the stability of the motion output .With the principle of inversion method, the cam contour curve and the swing arm contour curve are designed, separately, and the four groups of cams in the cam group are evenly staggered by 22.5° to ensure that at least one set of cams is in an effective push state during the operation of the mechanism to keep continuous motion output. The NX10 software is used to simulate the kinematics of the transmission mechanism. By analyzing the speed-time curve of the rocker arm under different gear ratios, the continuous and outputsmooth transmission output can be realized when the total transmission ratio of the CVT is within a certain speed control angle. The CVT can obtain a wide range of transmission and a large transmission ratio, which makes up for the shortcomings of the existing CVT, such as narrow range of transmission and small maximum transmission ratio.