The traditional A^* algorithm requires all the node information and neglects the width of the vehicle in practical application. To solve the problem, we proposed a new algorithm which is based on A^* algorithm and uses VFF method together. When using the new algorithm, problems such as that vehicle falls into local minima and swings violently when there are obstacles near the target can be avoided. The simulation results verify the effectiveness of the new algorithm. The experimental results show that the proposed algorithm widens the use range of the original algorithms and improves the ability of real-time navigation for unmanned vehicles.