In order to study the characteristics of chlorine saline soil and its influencing factors, the orthogonal test was carried out in laboratory based on the sandy chlorine saline soil along Qinghai Railway with the initial moisture content, chloride content, compaction degree and initial melting pressure as four main influencing factors. And the influence of these four factors on the chlorine saline soil was analyzed quantitatively through the fitting of the three-dimensional surface scatter plot, and the applicability of surface soil and subgrade filling soil along the railway from Xitieshan to North Hobxun in Qinghai area is demonstrated. The experimental results show that the salt content of NaCl has the greatest influence on the melting subsidence, the initial water content is the second, the initial immersion pressure and compactness have the smallest influence. Rational Talor relationship of subsidence coefficient of surface soil with initial water content, salinity, compactness, immersion load and subsidence coefficient was obtained.When the train speed does not exceed 250 km/h, the surface soil can be used as railway roadbed filling. While when the train speed exceeds 300 km/h, it can not be used as high-speed railway roadbed filling.