A single submarine must maneuver at high speed to carry out bearing-only target tracking passively.To solve the problem, a new method is proposed for a submarine to track a target stealthily by cooperation with Unmanned Underwater Vehicle (UUV).The UUVs are arranged at some distance away from a submarine, which communicate with the submarine by optical fiber.The command and control system of the submarine tracks the target by using observations of the submarine and UUVs, by which submarines can track target stealthily without making high-speed maneuvering.Results of simulations prove that the method has better tracking performance.