Abstract: Soild wastes exhibit great potential in improving saline-alkali land. This paper systematically reviews the application of typical solid wastes in the improvement of saline-alkali land with focuses on the improvement effect and mechanism of industrial solid wastes and agricultural/forestry solid wastes. The industrial solid wastes (desulfurized gypsum, phosphogypsum, fly ash, coal gangue, etc.) improve soil pore structure, reduce bulk density, promote ion exchange, adjust pH and accelerate salt leaching under the conditions of direct utilization and modified utilization. Agricultural and forestry solid wastes (chicken manure, cow dung, straw, etc.) play an improvement role in improving soil fertility, optimizing aggregate structure, and reducing saline-alkali stress. The future research directions are prospected, including waste composite utilization technology, long-term field monitoring and evaluation system construction and intelligent improvement technology, which could provide theoretical support and technical reference for solid waste recycling and sustainable management of saline-alkali land.