Search and rescue robots are important detection instrument platforms. To address the poor environmental adaptability of existing rigid-structured search and rescue robots, a design method for the search and rescue robot with crab-inspired rigid-flexible coupling mechanisms is proposed in this article. Firstly, the robot mechanisms are designed. Secondly, the lateral motion gaits of the robot are designed based on crab motion experiments, and the feasibility of the gait design is verified through simulations. Thirdly, the software and hardware systems of the robot are designed. Finally, experiments are implemented on the robot′s walking ability on multiple terrains. Moreover, tests of functions, including dark light environment adaptability, human detection, and obstacle avoidance capabilities, are carried out. The results show that this small-sized robot with simple control can realize basic motion functions, the maximum velocity and the minimum power consumption of the robot during the lateral motion is about 3. 4 cm/ s and 8. 6 W, and the angle range of the turning motion is ±90°. Furthermore, the robot adapts well to different terrains and environments and can complete search and rescue functions like environment perception and human detection.