With the proposal of network-centric warfare, it is particularly important to fully, effectively and reasonably use the sensor resources of each aircraft platform in the formation to improve the situation awareness ability in the complex confrontation environment in the formation cooperative combat environment. Aiming at the task allocation problem of multi-aircraft platforms cooperative search, the efficiency function of search task is established by factors such as search time, target discovery probability and the number of aircraft platforms used. In this paper, based on the engineering practice, the sensor capabilities are refined, and the search task airspace merging processing method is proposed, which improves the utilization of the limited sensor resources and sensor capabilities in the formation, and solves the task allocation problem in the multi-aircraft platforms sensor cooperative search. The improved contract network algorithm is used to solve the task allocation scheme. Simulation results show the effectiveness of the proposed method. The method proposed in this paper can be used to solve the task allocation problem of multi-aircraft platform collaborative search in engineering practice.