Based on URWPGSim 2D simulation platform, a linear optimization algorithm to transport items in water is put forward. Analyze the kinetic characteristic of the simulation robot fish. Introduces the point to point algorithm commonly used in 2D simulation robot fish, gives the optimized straight line algorithm and verify the algorithm by experiment. The experiment result shows that the optimization algorithm is able to enhance stability of the robot fish and better control, providing reference for other robot in water to control simulation fish at the same time.