According to a method for continuously measuring the
radon exhalation rate according to the change of a leakage coefficient and a back-
diffusion coefficient, before the leakage coefficient and the back-
diffusion coefficient are not changed, the effective decay constant is firstly measured, and the
radon exhalation rate is directly calculated through the effective decay constant. When rainfall or geological conditions are changed, and the leakage coefficient and the back-
diffusion coefficient are changed, each measurement period is set to be 2 to 60 minutes, n measurement periods are set as one group, m groups are continuously measured, m is an even number, the flow rate of the pump is L1 when the first, third, fifth,... and (m-1) th groups are measured, the flow rate of the pump is L2 when the second, fourth, sixth,... and m th groups are measured, and the difference between L1 and L2 is more than 20%; and the
radon exhalation rate and the effective decay constant are calculated through a formula by using the data of the first and second groups, the data of the third and fourth groups,..., and the data of the m-1 and m groups. According to the method, after the leakage coefficient and the back-diffusion coefficient are changed, the accurate
radon exhalation rate and the effective decay constant can still be obtained, and the calculation precision of the
radon exhalation rate is improved.