This article proposes a couple four-bar linkage mechanism for the cockroach robot, which integrates advantages of existing mechanisms. The novel mechanism has a good rigidity and a strong bearing capacity. It can be decoupling controlled and move agilely. Firstly, the movement performance of the mechanism including the backward and forward kinematics is analyzed. Secondly, a decoupling algorithm is presented to control the prototype. Then we analyze the important parameters of the hexapod, including the working space and the bearing capacity, and the result of the analysis proves that the mechanism has got an improved performance. The algorithm model is simulated by MATLAB and ADAMS. Ultimately, some experiments are carried out. The prototype is controlled to walk on the ground. We also add extra weight on it, in order to test the robot's load capacity. The experiment results show that the new mechanism design is reasonable and the analysis is correct.