According to characteristic of the city underground engineering, Combining the instance of underground pass in the rich water sands in the one city, the way of ground dewatering has analyzed and dewatering result of deep well has qualitatively analyzed to subside to the earth's surface, around building correctly subside at the same time. Observe results indicate that the way can be full of project needs. The paper has offered the construction example for the underground engineering in the rich water sand layer.