Abstract: Dijkstra algorithm is integrated into basic Rapidly-exploring Random Tree Algorithm and a new name, Improved Fast Search Radom Tree Algorithm, is given to the resultant algorithm. The kinetic path control rate is designed according to widely used inner-outer loop control concept which, with the optimized path as expectation input, better solves the underactuated ship path tracking problem. A neural network is used to approximate the unmodeled dynamics and external interference in the ship dynamics subsystem. The neural sliding mode controller responds to the rate guiding signal from the kinetics subsystem well. The system is verified through simulation experiments.