Indoor soil column simulation was used to study the improvement effect of saline soil under different irrigation volumes. The three different irrigation volumes in the experimental design were S1 (200 mm), S2 (300 mm), and S3 (400 mm). The results showed that:(1) Irrigation had a great influence on the leaching of soil salinity in 0-40 cm soil layer. Soil layer in 0-20 cm had the highest desalination rate, which performance was S3 > S2 > S1. Salt accumulation occurred in the profile of different irrigation volumes, and was observed in the 40-60 cm soil layer of S1 and S2, which indicated that low amount irrigation had leaching effect on the surface soil salt, but could cause salt accumulation in the bottom soil. (2) The contents of K⁺, Na⁺, Ca²⁺, Mg²⁺, Cl^-, SO₄^2-, and HCO₃^- decreased after irrigation, and the overall dissolution rate of salt ion increased with the increase of irrigation volumes. The variation of each ion showed different changes with the increase of irrigation volumes in 0-20 cm soil layer. Ca²⁺ firstly accumulated and then dissoluted, while HCO₃^- dissoluted firstly and then accumulated, and the other ions decreased with the increase of irrigation volumes. (3) After irrigation, the distribution of S1 and S2 pH in profile was similar to that before irrigation. The total alkalinity of 0-40 cm soil layer increased firstly and then decreased with the increase of irrigation amount, which was firstly alkalized and then alkali removed, and was consistent with the change of pH. The research results can provide reference for water-salt balance and water-saving irrigation in saline-alkali soil.