Abstract: In order to improve the quality and efficiency of crops in saline-alkali land, three groups of irrigation levels i.e. W1（268 mm）, W2（201 mm） and W3（161 mm） and three groups of fertilization levels i.e.（N-P₂O₂-K₂O, kg/hm~2） F1（260-200-220 kg/hm~2）, F2（208-160-176 kg/hm~2） and F3（156-120-132 kg/hm~2）, summing up to 9 groups of coupling treatments were set up. Based on the greenhouse experiment, the effects of water and fertilizer coupling on soil salinity, plant height, stem diameter, root characteristics, yield and quality of tomatoes cultivated in saline-alkali soil were studied. And the multi-objective optimization model of the genetic algorithm was constructed to determine the optimal water and fertilizer regulation strategy for tomato cultivation in saline-alkali soil. It turns out that compared with CK, the plant height, stem diameter, root characteristics, water and fertilizer utilization efficiency, yield and quality of tomatoes cultivated in saline-alkali soil have significant advantages. The salt content in the surface soil of the substrate treatment is low, the soil profile of 0-30 cm shows a salt accumulation process, and the soil profile of 30-60 cm shows a desalination process. Through the VIKOR method of AHP-CRITIC subjective and objective combination weighting, the yield and flavor quality of tomatoes were evaluated. The benefit ratio of W3F1 treatment is the smallest, and the yield and quality are the best. Based on the genetic algorithm multi-objective optimization model to solve the Pareto optimal solution, the optimal water and fertilizer coupling strategy for tomato cultivation in saline-alkali soil is determined to be W3F2. This study can provide a theoretical basis for the scientific management of water and fertilizer for high-quality fruits and vegetables in saline-alkali soil.