The problem of how to design the multi-UAV formation autonomous reconfiguration is studied. Based on three kinds of cost functions,the nonlinear dynamic equations of UAVs and four inequality constrain conditions,a nonlinear multi-objective optimization model is constructed. After applying weighted sum method and separating all equality constraints from inequality constraints,the former nonlinear multi-objective optimization model is converted into a standard nonlinear single-objective optimization model. Then the interior point algorithm from operations research is used to solve the optimization problem. To avoid rank deficiency,some improvements are made in realizing the interior point algorithm. The equivalence property between multi-objective optimization through weighted sum method and single-objective optimization is proved. Finally,the efficiency of the proposed strategy is confirmed by the simulation results.