The invention discloses a method for conducting afforestation on saline-alkali soil. The method includes the steps of firstly, digging deep planting pits in the saline-alkali soil; secondly, paving two layers of isolating curtains at the bottom of each planting pit and the inner wall of each planting pit respectively; thirdly, arranging filtering layers between each isolation layer and the bottom of each planting pit and between each isolating layer and the inner wall of each planting pit; fourthly, preparing mixed matrix, filling the matrix into the pits and tamping down the matrix; fifthly, planting seedlings; sixthly, conducting maintenance management. According to the method for conducting afforestation on the saline-alkali soil, the difficult problems of lowering the salt content, improving the soil and conducting afforestation on the saline-alkali soil are solved. Through the measures of discharging salt and blocking salt, the salt content in the distribution range of the plant root systems is lowered, the plant root systems are promoted to absorb nutrient and water and discharge salt in a unidirectional mode, and a soil environment which is beneficial to plant growth is created. According to the method for conducting afforestation on the saline-alkali soil, the survival rate and the preserving rate of the seedlings are improved, and the method is low in cost compared with a traditional method for improving the saline-alkali soil by merely paving the salt isolating layers, replacing soil and conducting afforestation, is suitable for the saline-alkali soil afforestation and the plant cover recovery project, and can also be used in the manual construction and the machine and human coordinated construction.