Considering the fight conflict problems between Unmanned Aerial Vehicles (UAVs) and other aircrafts, we proposed a novel path planning algorithm without collision based on the disturbance fluid. The relative initial fluid is constructed based on the movement information of intruder. Then, the influence of intruder on the relative initial fluid is quantized by the disturbance matrix. The relative modified flow is obtained by the modulated relative initial fluid, and then the actual streamline is obtained, which is the planned flight path without collision. Meanwhile, considering the UAV's performance constraint, dynamic optimization is made to the reactivity parameter by using the receding horizon optimization method to ensure that the planned path is flyable. Simulation result shows that the algorithm can make real-time path planning with collision avoidance, which can satisfy the requirements of UAVs.