A strategy based on Markov Decision Process (MDP) was proposed to solve the air-to-ground attack operation planning problem for manned/unmanned aerial vehicle formation. Firstly, according to the characteristics of combat operations of manned/unmanned aerial vehicle formation, the forming method of the state set and action set was proposed, and the method for calculating the state transition probability and reward function of MDP model was designed. Then, with consideration of the resources and time constraints, the MDP optimization model was established to execute the operation planning. After that, we made improvements to the Ant Colony Algorithm (ACO) on the path selection probability and pheromone updating method to solve the MDP optimization model. Lastly, a simulation analysis was carried out. The result showed the proposed method can obtain a good solution to the operation planning problem for manned/unmanned aerial vehicle formation with high calculation speed.