Abstract: Objectives Inspired by remora, a robotic remora which can adhere to diverse hosts and travel with them for a long distance with low energy consumption due to the special adhesion ability, solves the problem of low endurance in the robotic fish. Methods A prototype with three dimensional motion decoupled, high mobility and responsive vertical motion is developed. Moreover, the wire-driven propulsion mechanism and pectoral fins diving mechanism are adopted to realize high mobility and decoupled motion. Besides, a central pattern generator is adopted to realize high biomimetic swimming posture and smooth switching of motion modes. An active rejection disturbance controller is developed to achieve robust, fast and precise heading control under model uncertainty and the environment disturbance. The swimming, diving and heading control experiments are conducted. Results The results indicate that the designed robotic remora owns the high mobility and responsive decoupled motion ability, with the max swimming speed of 0.17 m/s and max ascent and descent speed of 0.095 m/s and 0.0995 m/s respectively. The designed heading controller can achieve fast and precise control, which is with better performance than the PID controller. Conclusions This study, which gives the design of the robotic remora and verifies the decoupled motion and the heading controller by experiments, lays the foundation for the auto adhesion of the robotic remora.