The challenges and demands of underwater war in navy is analyzed in the paper. It is proposed that simulation technology, as the "multiplier" of underwater combat efficiency improvement, should further strengthen the modeling and simulation research of complex underwater environment and target characteristics, give full play to the cooperative combat capability of underwater weapons in complex battlefield environment, with combat simulation technology results and improve the overall operational efficiency of underwater weapons from the perspective of combat use, support army to win the collaborative and systematic high-intensity confrontation that may occur in the underwater domain in the future.