Abstract: Tomato（Lycopersicon esculentum Mill.）,eggplant（Solanum melongena L.） and pepper（Capsicum annuum L.） were used as the test materials, six treatments were designed by plug seedling method, full spectrum, red and blue 2∶1,red and blue 3∶1,red and blue 5∶1,red and blue 7∶1,natural light（CK）.The effects of different proportions of red and blue light combinations on the growth and photosynthetic characteristics of solanaceous vegetable seedlings were studied, in order to screen out the most suitable LED lamp formula for solanaceous vegetables seedling.The results showed that the plant height of tomato and pepper treated with red and blue 5∶1 was the maximum.With the increasing of the proportion of red light, the effect on the stem diameter of tomato and eggplant was not significant, and the leaf area and biomass increased first and then decreased.Pepper had the largest leaf area, biomass and chlorophyll a/b ratio in red and blue 7∶1 treatment.Under the treatment of red and blue 5∶1,the three vegetables all reached the maximum photosynthetic parameter value, but it showed a downward trend at red and blue 7∶1.The evaluation results of membership function method showed that the membership function value obtained by red and blue 5∶1 was the highest and ranked first, which could be used as a general formula in the cultivation of solanaceous vegetables.