Abstract: Organic substrate cultivation in solar greenhouse in Hexi area is an ecological planting mode to make rational use of Gobi wasteland, light and heat resources and realize the recycling of agricultural waste resources. Tomato is planted in multiple cropping and continuous cropping, with large amount of fertilization and inaccurate fertilization proportion, resulting in the enrichment of a large number of elements in the substrate, low fertilizer utilization rate and common secondary salinization of the cultivation substrate, which has a great impact on the growth, yield and quality of tomato. Based on the Gobi solar greenhouse, the fertilizer demand of tomato cultivated on organic substrate was studied. The results showed that when the ratio of N∶P₂O₅∶K₂O is 27∶13.5∶40.5, the plant growth was moderate, the yield was the highest, the quality was better and the commodity was better.