Aiming at the situation that the robot is multi-driven and has complex kinematical characteristics and control system,a waist structure of robot with dodge function is designed,which has the characteristics of single-drive,multi-degree of freedom,simple structure,accurate and easy motion classification. The kinematical principle of the structure and the selection of the relevant initial parameters are introduced and the coordinate transformation matrix of the upper body under different conditions is obtained by Denavit-Hartenberg（ D-H） method. The positive and inverse solutions of the robot are obtained. Finally,the three-dimensional model of the structure is built,the model is simplified and imported into ADAMS software for kinematics simulation analysis and the results are verified by experiments.