Currently, pump & treat, which is one of the common repair contaminated soil methods, could get rid of some pollutants efficiently. However, it's very limit for poor permeability and low concentration pollutions. In consideration of the property that water would shift from unfrozen region to freezing front and soil permeability will also enhance by freeze-thaw action under certain conditions of temperature gradients and moisture, the pump & treats extraction productivity was explored in experimental research throughbasic experiments. Clay mixed with NaCl (simulation of heavy metal pollutants) is used as the study object and experienced the unidirectional freeze-thaw and pollutants cleansing test, The feasibility of freeze-thaw action flush pollutants is explored. The experimental results show that the freezing and thawing action is contribute to advancing pollutant removed efficiency and a reliable experimental basis is provided for the following implementation of the situ soil flushing.