According to the anti-warship warfare characteristic of warship formation, the synthesis object function which is based on synthetically thinking over multi-factors, such as object damage, object value, troops consume and the object damage degree demand is constructed. Genetic Algorithms is applied to solve the fire assignment problem of anti-warship missile, and the simulation outcome of the example is analyzed. The model and the method are indicated to be effective, and it can supply reference to the fire assignment problem of the missile attacking object in the anti-warship warfare.