Urban underwater interchange tunnel structure

The utility model discloses an urban underwater interchange tunnel structure which comprises a main line tunnel and ramp tunnels. The main line tunnel passes through a water system downward, two ends of the main line tunnel are connected with a ground wiring road, one ends of the ramp tunnels are connected with the main line tunnel, the other ends of the ramp tunnels are connected with other ground surface roads, and underground flyover crossing relation is formed between the main line tunnel and the ramp tunnels or between the ramp tunnels. According to the structure, the ramp tunnels are additionally provided to connect the main line tunnel at one ends and other ground surface roads at the other ends so as to form an underground interchange on the premise that new underwater corridor belts are not added and line position of the main line tunnel is not changed, therefore utilization rate of the underwater corridor belts is improved to the utmost, and the traffic function of tunnels is brought into full play.