The risk of radioactive material leakage caused by nuclear accidents increased with the increasing of number of Nuclear Power Plants in China. One of the serious threat of radiation harm to the human body is believed to be 137Cs. It can exist in the environment for a long time, due to the half-life of which is as long as about 30 years. In this research, the brown soil and aeolian sandy soil were selected as two kinds of classic soil around the site of Shidaowan demonstration plant of CAP1400 to carry out the 137Cs migration model experiments. The source of radioactivity was put on the 16 of experiment columns that were filled by undisturbed soil, the simulated raining weather was according to the local rainfall amount with two sprinklers, and the sunlight was replaced by fluorescent lamp. The result showed that the vertical migration model of radionuclides in soil is one-dimensional convective dispersion equation. three-year experiments showed that most of 137Cs in soil were distributed in the range of 0–4cm. The simulation results using the Hydrus 1D with 10 years that most of 137Cs in soil were distributed in the range of 0–10cm, so the nuclear accident caused by the serious nuclides have little impact on groundwater.