In order to analyze the Lop Nur area's sulfurous saline soil salt-frost expansion change rules and influences during each freeze-thaw cycle, we adopted the method of controlling initial water content and dry density to experiment the freeze-thaw cycle tests. The results indicate that the sulfurous saline soil's salt-frost expansion rate in each freeze-thaw cycle is a quadratic function, which firstly increases and then decreases. Under the influence of the freeze-thaw cycles, the salt solution's concentration decreases and the soil's interior structure reaches a critical point. The test indicates that after four cycles each cycle's salt-frost rate slows down. The growth rate of the early four circle stages for the salt-frost expansion accelerates after slows down, and this rule could be more obvious with the increase in water content. The damage of soil's structural could be the main reason for the early stage salt-frost heave rate increase. With the dry density increasing the energy for salt-frost which helps change the porosity and structure enlarged, and this experiment phenomenon shows the salt-frost heave rate of each cycle could be more unstable. The result proves that the sulfurous saline soil's salt-frost expansion in each freeze-thaw could have a close relation with the status of soil structure in different cycles.