The underwater path planning of amphibious spherical robots is currently a research challenge in the field of amphibious robot motion control. In this study, two types of robot motion control algorithms, namely Generalized Constraint Optimization (GCOP) and Sequential Quadratic Programming (SQP) algorithms based on visual servo, were compared and analyzed.The optimal path planning of the amphibious spherical robot was realized, combinated with visual servo sensors.Dynamic target calibration, moving target monitoring, underwater obstacle recognition, and target trackingfunctions were also developed. Furthermore, this study considered the symmetrical structure of spherical robots(using Archimedes′ buoyancy principle) and combined fuzzy control algorithms to control the water level of the water tank so that spherical amphibious robots can achieve multi-DOF underwater motion. Finally, algorithm simulations and underwater motion experiments were performed to verify the feasibility of the proposed method.The results show that path planning by the SQP algorithm is more reasonable considering the distance between the GCOP and SQP algorithms, relative to the obstacle. In reaching the target coordinate position, the error between the two algorithms reaches to 167.5 mm, showing that the SQP algorithm is superior in underwater path planning than the GCOP algorithm.