To realize coordinated searching tasks of aeronautic swarms in unknown areas, a greedy iterative decision-making method based on distributed model predictive control (DMPC) is proposed. First, a swarm-aerial-vehicle movement model is built to analyze their moving characteristics, and the search information graph model is used to describe the changes of dynamic targets in unknown environment during the searching task. Then, the Markov chain is used to characterize and forecast the target's potential movements. Finally, on the basis of DMPC, a greedy iterative algorithm of the random decision-making sequence is adopted to find solutions. The stability and convergence of the proposed method are also analyzed. Simulation experiments prove the feasibility and superiority of the proposed method.