Snake robots have broad application potential, but their motion-control and motion-planning problems are extremely challenging due to the high redundancy of degrees of freedom (DoFs), and the lack of complete system tools further hinders the research of snake robots. In this paper, a coordinate system and a kinematic model were established based on the D-H method for snake robots. The rhythm-generation model for multimodal motion gait and a novel sliding-window five-point interpolation-derivative model were proposed based on a bio-inspired central pattern generator (CPG) model. A prototype and simulator were constructed based on the designed snake robot models to achieve the multimodal motion gait for the snake robot and improve its environmental adaptability. Furthermore, a novel structure–drive–perception–control integration snake robot system (SnakeSys) was built based on the robot-operating system (ROS). Finally, the effectiveness, feasibility, and accuracy of the kinematic model and control model in motion control and information perception were verified through simulations and experiments. We open sourced SnakeSys so that relevant researchers or developers can directly utilize or further develop it.