In order to determine the main parameters affecting the kinematic performance of the quadrupedal bionic horse robot, this paper investigates the sensitivity analysis of structural parameters on performance changes. Based on the introduction of the structure of the bionic horse robot used for equine-assisted therapy, the establishment of a kinematic model, and the kinematic analysis by the closed-loop vector method, the kinematic relationship between the trajectory of the foot end of the bionic horse and the structural parameters is calculated by full differential calculations, and the influence laws of the changes of the structural parameters on the change of the trajectory of the foot end of the bionic horse are analyzed, and the indexes for evaluating the sensitivity of the structural parameters are introduced, so that the key structural parameters with high sensitivity to the robot performance are obtained. The results are verified by simulation. This research lays the foundation for further optimization of the structural parameters of the robot.