In this paper, a variety of methods for measuring radon were used to evaluate the radon concentration in the air and water radon in the underground neutron laboratory of the Daya Bay reactor, as well as the wall of the hall, and the rate of precipitation of the pool wall. The measurement data show that the values of the radon outflow rate at different locations on the walls of the underground lab hall in Daya Bay are quite different, but the radon concentration in the pool still shows a higher phenomenon near the wall of the pool. Nitrogen seal...