Secondary salinization problem of soil in Qinwangchuan irrigated regions has increasingly become the focus of attention since the Yindaruqin irrigation project was completed. In this paper, statistical and comparative analyses were used to study the farmland soil ions under different time and spaces in Qinwangchuan irrigated regions. The results showed that, among the eight ions of farmland soil, the highest concentration of anion was SO42-, the lowest concentration of anion was CO32-, which reaching almost zero, and the highest concentration of cation was Na+, the lowest concentration of cation was K+. The main soil salts included sodium sulfate, calcium sulfate, sodium bicarbonate and sodium bicarbonate and so on. There were some correlation between different soil ions, which reflected sedimentology characteristics of soil salts and their differentiation relationship in different soil profiles. Under the influence of the various factors (irrigation, evaporation, precipitation, cultivation, and so on), soil salt content was a dynamic process with time, and this process would reach a balance at some point in time which could be broken up if some new factors joined in.