Double-crank ring-plate-typed pin-cycloid gear planetary drive conquers shortcomings of a traditional pin-cycloid gear planetary drive, whose load-capacity is restricted by rotation-arm bearing dimension. The load-capacity of this kind of new drive is improved greatly and the efficiency of whole machine is 94%. In order to know dynamics reliability of this drive , nonlinear characteristics of double-crank ring-plate-typed pin-cycloid gear planetary drive are analyzed from two sides of transmission error and dynamic meshing process in this paper. A sensitive analytic mathematic model of rod dimension error is set up by kinematics theory. Based on ring-plate-type cycloid drive dynamic meshing characteristics, a rigidity-flexibility combined model of pin-cycloid planetary drive is set up by ANSYS/LS-DYNA module. Meshing process between pin-cycloid gear is simulated by FEM. Instantaneous stress, distortion and dynamic meshing rigidity are computed. Analytical results show that nonlinear meshing rigidity and transmission errors are two main dynamic exciters which cause prototype to vibrate. So, rod dimension error should be reduced in order to increase meshing accuracy, and meshing rigidity of new prototype should be increased in order to reduce vibration. Nonlinear characteristics of the drive can offer some theoretical bases for design of new prototype.