Aiming at the problem of multi-aircraft conflict, a real-time conflict resolution method based on Cooperative Game was proposed. Firstly, a Cooperative Game conflict resolution model was constructed, and the maximum coalition welfare solution is introduced to balance the interests of all participants; Secondly, the evaluating indicators of conflict resolution effectiveness were established, Simultaneously, the Utility Function and the coalition welfare function were put forward; Finally, the particle swarm optimization (PSO) algorithm is adopted to minimize the calculation time in the solution. From the simulations of three and six aircrafts conflict we can know this method can find the equilibrium point that maximize the coalition welfare function value and obtain the optimal strategy of multi-aircraft conflict resolution.