Abstract: A new "separated → partly constrained → fully constrained" progressive docking method and a claw-shaped docking mechanism are presented to fulfill rigid docking operation between robots in rugged terrain. This mechanism can achieve attitude adjustment in pitch and yaw directions, and control flare angle between two grippers by changing cam slot form. This claw-shaped docking mechanism can fulfill multiple tasks such as object-grasping, rigid docking and mutual cooperation among multiple robots. Kinematics of this mechanism is analyzed. The workspace, and forward and inverse kinematics of this mechanism are deduced. JL-2 modular mobile robot system based on this mechanism is developed, and performance of the proposed claw-shaped docking mechanism is verified by experiments. The results prove that this mechanism has strong offset rectifying capacity and large grasping range to accomplish multiple tasks such as docking and cooperation in multi-robot system.