The effects of different concentrations of organic liquid fertilizer and irrigation lower limit on the growth，yield and quality of greenhouse substrate cultivated lettuce were studied，and the theoretical basis for high quality and high yield of lettuce was studied.The test took “Fulandri” lettuce as the test material，the matrix ratio of peat soil∶vermiculite∶perlite=2∶1∶1 was adopted，with 20 kg chicken manure per cubic meter of matrix.Taking water as control(CK)，3 irrigation solutions were adopted:N1 was nutrient solution formula(EC is 1.8 mS·cm-1)，N2 was low concentration organic liquid fertilizer(EC is 1.2 mS·cm-1)，N3 was high concentration organic liquid fertilizer(EC is 1.8 mS·cm-1).And 3 irrigation limits were set up:G1，G2 and G3 were 60%，70% and 80% of the maximum water capacity of the matrix，respectively，there were 12 treatments in total.The results showed that the growth status of lettuce was the best at the G2 treatments，with 20 kg of chicken manure per cubic matrix.Treatment of organic liquid fertilizer with EC of 1.2 mS·cm-1 effectively promoted the growth of lettuce plant size，leaf area，biomass and SPAD value，but with EC of 1.8 mS·cm-1，lettuce growth was inhibited.For the 70% irrigation treatment，the nutrient solution-treated lettuce has the highest yield and irrigation water use efficiency，followed by the organic liquid fertilizer with an EC of 1.2 mS·cm-1，which also effectively increased the lettuce yield and improved the water use efficiency.Irrigation with organic liquid fertilizer significantly increased the content of vitamin C and soluble protein in lettuce，and increased with the concentration increase.It also significantly reduced the nitrate content in lettuce，with the lowest organic liquid fertilizer EC of 1.2 mS·cm-1.In conclusion，when the lower limit of irrigation is 70% of the maximum water quantity of the matrix，and the organic liquid fertilizer EC is 1.2 mS·cm-1，the lettuce production can be ensured，the nitrate content can be effectively reduced，and the quality can be improved，compared with other treatments.This study can provide a reference for the whole organic production of lettuce.