The UAVs have limited detection range and can carry limited consumable payloads.Therefore, when it requires different types and different quantities of payloads to completely destroy a detected target, a team of UAVs, called a formation, is needed.A multi-UAV formation for taking search and strike mission was proposed, which ensured the minimum delay of target attacking and the minimum scale of formation through two phases.Three search strategies:random search strategy, multi-lane based search strategy and grid based search strategy, were given.At last,Monte-Carlo simulation was used to implement the formation algorithm and analyze the performance of three search strategies.