With the development of Anti-Access/Area Denial weapons，the surface advantage of the U.S. Navy to the other countries are becoming smaller and smaller，and the undersea battlefield is becoming more and more important for the U.S. Navy to demonstrate its military strength and obtain the initiative in the battlefield. Now， undersea warfare has become one of the key areas for U.S. Navy’s development. Based on the review of the development of U.S. Navy’s undersea warfare concepts，this paper analyzes the new threats and challenges faced by the U.S. Navy in future undersea warfare，and researches the equipment development for the U.S. Navy in response to future underwater warfare in combination with the current condition of the US Navy.
