Multiple vehicles coordinated target assignment is the key problem to improve the efficiency of team fighting in the mission of multiple vehicles attacking multiple target regions. A route planning method for this problem was presented with consideration of the differences in vehicle ability, cooperation mode and the abrupt change of the battle field situation. Based on the evaluation of vehicle residual ability, a mathematical model of multiple vehicles coordinated target assignment had been built. The target assignment schemes were chosen by constraints on the vehicle residual ability, then the integrity of the military strength was ensured. The final simulation results of this model show that a stronger adaptability for abrupt change of mission objective can be gained.