Abstract: In order to reduce the radiation hazards of radon and radon in the uranium mining process to underground workers and improve the protection level effectively, it is necessary to master the transmission law of radon in the underground medium of uranium mine and the factors affecting the migration distribution of radon concentration, and on this basis, it predicts the implementation of a project by software simulation. The effect of radon reduction can be achieved. According to the design drawings and the situation of field mapping, the model of the middle section of the mine is established by ANSYS Workbench 15.0 software, and the model is divided by unstructured grid, and the wall area of the ventilation pipe is encrypted. After the grid quality meets the calculation requirements, the overall simulation of the downhole wind field and the screening of the poor air flow position are completed first. On the basis of this, some measures are put forward to change the length of the ventilation pipe, and the radon initial concentration, radon exhalation rate, wind speed, wind and wind are carried out. Parameters such as pressure, temperature, humidity and smoothness of the wall are set up. Finally, the simulation results of radon concentration in underground are obtained. The comparison shows that after the change of the length of the underground ventilation pipe, 29 points radon concentration in the 31 points of concern are reduced, only 2 points radon concentration increase and the overall radon reduction effect is good, which can provide theoretical basis for the real implementation of the follow-up project.