Nitrogen nutrition is an essential macro-element for crops. Different forms of nitrogen nutrition significantly affect the absorption and physiological metabolism of crops，thus affecting crop yield and quality. Vegetables and tobacco are typical nitrate-preferring crops，but recent studies have found that appropriate supplement of ammonium can improve crop yield and quality effectively. However，there is a lack of robust verification by analyzing large samples，which leads to no definitive conclusion being formed. A total of 77 studies that analyzed the effects of different ammonium and nitrate nitrogen ratios on the growth of vegetables and tobacco crops published from 2000 to 2022 were collected to build up new dataset. The Meta-analysis was used to evaluate the comprehensive effects of different ammonium and nitrate nitrogen ratios on the yield，quality and photosynthetic characteristics of different crops，in order to provide scientific support for improving nutrition management level. Totally，vegetables and tobacco preferred nitrate nitrogen，but compared with the pure nitrate nitrogen supply，adding a certain proportion of ammonium significantly increased crop biomass，and the best proportion of ammonium nitrogen was less than 50%. Under this ammonium-nitrate ratio，leaf vegetable biomass and solanaceous vegetables biomass increased by 11.3% and 8.4%，respectively. When the proportion of ammonium nitrogen increased to more than 50% or 100% supply，the biomass of vegetable crops decreased or showed no significant improvement effect. The change of soluble protein content showed different trend. The content of soluble protein in leafy vegetables increased by 42.2% when ammonium was dominant(>50∶50)，and the content of soluble protein in solanaceous vegetables increased by 22.7% when nitrate was dominant(<50∶50). The vitamin C content in leafy vegetables increased the most only when the proportion of ammonium was ≤ 50%. For tobacco，when the supply of ammonium and nitrate nitrogen was balanced(50∶50)，the yield and physiological indexes achieved the best levels，for example，compared with pure nitrate treatment，the biomass increased by 22.1%. At the same time，when ammonium and nitrate was balanced(50∶50)，the chlorophyll contents in vegetable crops and tobacco showed the highest. The above effectively confirmed the positive effect of appropriate ammonium-nitrate nitrogen ratios on crop biomass and quality in vegetable and tobacco production. Notably，it was necessary to ensure that the proportion of ammonium was lower than that of nitrate to avoid yield reduction and quality decline. This study provided scientific support for better nitrogen nutrition management of vegetable crops and tobacco.