We studied the ion content and particle size of soil that modified by four treatments, with the severe saline-alkali soil of Zhaodong City, Heilongjiang Province. Four treatments were CK(Control), Bar treatment(Small hole improvement-Bar foraging ditch-In situ repair), Cross treatment(Small hole improvement-Cross foraging ditch-In situ repair) and Grid treatment(Small hole improvement-Grid form of foraging ditch-In situ repair). Different improvement treatments changed the severe saline-alkali soil ion content dramatically, and significantly improved the soil activated Al content, the content of exchangeable Ca, and Mg(P＜0.05). The sulfate content, chlorine ion content, and carbonate content in the soil were significantly increased(P＜0.05). The granulation of soil was observed under the scanning electron microscope(SEM), and the fragmentation degree, and porosity were increased significantly. Therefore, three different improvements of saline-alkali soil made the soil composition and physical structure different from the original saline-alkali substrate, and effectively improved the soil salinity.