In order to deeply understand many walking gaits of hexapod robot in unstructured terrain and some relative factors of adapting various obstacles, an articulated leg model with six degree-of-freedom (DOF) is built in the initial researches. Based upon the designed six-DOF leg mechanism, a hexapod robot with total 42 DOFs is constructed, which can realize omni-directional movement. The tripod gait of hexapod robot is simulated. According to the leg mechanism and its model, kinematic angular displacement, angular velocity and angular acceleration of each joint of each leg can be analyzed. Therefore the detailed movement information can be obtained. Such researches provide good theoretical base for future dynamic analysis.