Soluble anions are important parts of soil salinity and have an important impact on plant growth and development.In order to explore the inversion accuracy of the soluble anions of the soil in the measured spectrum，in this study the salinized soil in Pingluo county in the northern Yinchuan area was taken as the research object，and 6 conventional transformations[smooth R，smooth reciprocal 1/R，smooth Logarithm lg(R)，smoothed reciprocal logarithm lg(1/R)，smoothed first-order differential R′，smoothed second-order differential R″]in preprocess were selected，and then correlation analysis and stepwise regression were used to screen ions’ sensitivity characteristics.Finally，principal component regression(PCR)，partial least square regression(PLSR)and support vector machine(SVM)were used to establish the soil anion inversion model.The results showed that:1)The content of Cl- and SO42- in the study area were higher than others，and the content of CO32- was the lowest，indicating that the soil in this region belongs to chloride saline soil.2)The original reflectance had the strongest correlation between the contents of anions and reflectance through R″ transformation，and the correlation coefficients of CO32-，HCO3-，Cl- and SO42- were 0.572，0.741，0.802 and 0.545，respectively.3)Compared to correlation analysis，stepwise regression (SR)could solve the problem of collinearity between spectra，and the inversion accuracy was higher.4)Compared to PCR and PLSR，the soluble anion inversion model built by SVM had the best effect.The best model for soil CO32-，Cl- and SO42- inversion was R″-SR-SVM.Among them，modeling coefficient of determination(Rc2)，verification coefficent of determination (Rp2) and relative prediction deviation (RPD) of the inversion model of CO32- was 0.984，0.560 and 6.76；Rc2，Rp2 and RPD of the inversion model of SO42- was 0.970，0.841 and 5.59；Rc2，Rp2 and RPD of the inversion model of Cl- was 0.925，0.940 and 3.62，respectively.The best model for soil HCO3- inversion was R′-SR-SVM.Rc2，Rp2 and RPD of the inversion model of HCO3- was 0.970，0.840 and 5.59，respectively.The research results could provide a theoretical basis for the inversion of soil salinization in this area and similar areas.