To explore the differences and characteristics of the effects of different biochar additions on salinity and ion leaching in saline soil. This study used indoor soil column simulation experiments to add 0.5% of pig manure (PMB), cotton straw (CSB), and maize straw (MSB) biochar to the soil surface (0-10 cm), the leaching process was divided into three stages: rapid descent (P1), slow descent (P2), and stable descent (P3). To investigate the leaching effect of different biochar on salt ions in saline soil of southern Xinjiang, the infiltration rate, flow rate, cumulative leaching concentration of anions and cations, soil profile moisture content, and residual soluble ion content were measured. The results showed that compared to the treatment without adding biochar (CK), the application of biochar could improve the flow rate and infiltration rate of the leachate at each stage. During the rapid decline in electrical conductivity stage, the flow rate of CSB treatment increased by 20%, and the infiltration rate of PMB treatment increased by 29%. MSB treatment first reduced the EC value to 5 mS/cm, but the improvement in ion removal ability was small. The application of biochar had a certain impact on the sequence of ion leaching at each stage, that was, it promoted the leaching of Ca²⁺, Na⁺, SO₄^2-, and Cl^-, and inhibited the leaching of K⁺. At the end of leaching, biochar can significantly reduce the residual salt content of soil. CSB treatment can improve the water retention capacity of topsoil, keeping the sodium adsorption ratio (SAR) always at a low level and providing the best elution effect for residual anions in the soil. This shows that CSB treatment is a potential soil conditioner. The results provide theoretical reference for salinized soil improvement in southern Xinjiang.