The biogeography-based optimization （BBO） algorithm is applied to the optimization of the firepower strike target allocation， and combined with a three-dimensional mutation operation to optimize the convergence accuracy of the algorithm. The improved three-dimensional variation biogeography-based optimization （Tdv-BBO） algorithm is used to solve the problem of target allocation in fire strike， and the target-fire quantity combination optimization is performed on the enemy scenario. The verification results of numerical examples show that the improved BBO algorithm enhances the global search capability， and can provide an effective method for the target assignment of joint maritime strikes.