Naval ship formation is one of the main counterwork forms in modern sea battles. Reliability theory is used to study naval ship formation deployment. First, a measure method for the cooperative quality of the shipborne equipments in the formation is given based on the concept of reliability degree. Then an optimized deployment of naval fleet is established with consideration of the cooperative quality of the shipborne equipments, and a solving algorithm based on Genetic Algorithm (GA) model is proposed. The effectiveness of the model is proved with massive simulations.