Snake-like robots can locomote effectively in complex terrains through changing boby shape. However, the traditional integrated design of snake-like robots has some challenging problems, such as low efficiency in rescue and search, difficulty in maintaining robot body, and inferior agility. In order to address these problems, a novel reconfigurable modular robot is developed and multiple motion modes are correspondingly analyzed in this paper. Specifically, the newly developed snake-like robot can be reconfigured by any number of modules through the connection mechanism, wherein each module of the robot integrates communication, power, actuator, and control units, therefore, all modules can behave independently. Besides, the novel connection mechanism between two modules is composed by hook and bolt which are helpful for free switch. Additionally, multiple motion modes are analyzed in this paper, specifically including mobile robot locomotin mode, serpentine mode, sidewinding mode, traveling wave mode, climbing mode, and auto-separation mode. Moreover, the climbing motion of the whole robot and the turning motion of a single module are thoroughly analyzed. Finally, sufficient experiments are performed to verify all motion modes using the developed snake-like robot.