Aiming at the path planning problem of four-wheel independent steering (4WIS) vehicles, a graph search algorithm integrated with mode decision is proposed. Firstly, three motion modes of 4WIS vehicle are modeled, and the motion characteristics of each motion mode are analyzed. Based on this, a multi-mode node expansion strategy is designed to realize the integration of 4WIS vehicle multiple motion modes and path planning. Then, a multi-objective cost function is designed to guide 4WIS vehicles to switch motion modes reasonably and generate a smooth path for optimal node selection and motion mode decision-making. Finally, the simulation experiment is carried out on MATLAB software, and the proposed algorithm is tested in various scenarios to verify the feasibility and effectiveness. The results show that the proposed algorithm considers the optimization combination and mode switching of three motion modes in path planning, and can achieve the optimal motion mode sequence and the shortest path planning. This algorithm has high solving efficiency and excellent planned path, and can fully utilize the high flexibility and trafficability of 4WIS vehicles, effectively solving their path planning problem.