To address the challenge of numerous and complex constraints in real mission environments, this paper proposes a real-time mission planning method based on constraint priority management to enhance the adaptability of UAV swarms in complex scenarios. First, UAVs with simultaneous heterogeneity in flight performance and payload are modeled, while complex cooperative targets with a series of temporal and spatial constraints are considered to ensure UAV and mission realism. Then, mission planning based on constraint priority management is employed to plan mission in real time while ensuring that all the constraints introduced are satisfied without conflict. Finally, flight parameter experiments display that a swarm consisting of UAVs with different ranges reduces the total distance traveled. Full-constraint simulations demonstrate that the method achieves conflict-free mission planning in around 5 ms, even with 10 different constraints, highlighting its significant potential for adaptation in realistic corresponding environments.