Abstract: With 3D movement0s ability and rhythmic locomotion mode, a nature snake makes itself survive in rugged terrains. The rhythmic activities of most creatures are generated by the CPG (Central Pattern Generator). Based on this fact, the sustained-type neuron has been adopted to construct a cyclic inhibitory CPG model for a snake-like robot whose joints are perpendicularly connected in series. The cyclic inhibitory CPG was proven to be able to generate rhythmic output with the least number of differential equations. The neuron network organized by the CPGs connected in line with unilateral excitation has been introduced to control the 3D locomotion of the snake-like robot, and then the necessary condition is also presented for the CPG neuron network to sustain a rhythmic output. By implementing this control architecture to a simulator of a snake-like robot, preliminary parameters of the CPG neuron network for its 3D locomotion are obtained. Moreover, it is known that“Perambulator”can successfully exhibit 3D locomotion by using the output of the proposed CPG network. The obtained results have also provided a brand-new approach to understand the unknown neuron network of nature snake.