In order to solve the control problem of formation maintenance and reconfiguration of small UAV, a controller suitable for formation maintenance and reconfiguration is designed. The small fixed-wing UAV is taken as the research object, the leader-wingman formation mode is adopted, the relative motion relationship model is established, the position and attitude deviation of the UAVs is analyzed and the controller acting on the speed and lateral channels respectively is designed. The six-degree-of-freedom model simulation system is used to test the formation performance. The simulation results show that the algorithm design can realize formation maintenance and reconfiguration, and meet the performance requirements.