To determine the application effect of liquid organic carbon fertilizer in low-temperature environment, a pot experiment was used to simulate the low-temperature environment in the early stage of flue-cured tobacco transplanting in an artificial climate box. The effects of liquid organic carbon fertilizer on the growth, dry matter accumulation and distribution, leaf SPAD value, malondialdehyde content, nitrate reductase activity and oxidase activity of tobacco seedlings under low-temperature stress were studied. The results showed that the application of liquid organic carbon fertilizer with suitable concentration (1.25-3.75 g/plant) could increase the dry matter accumulation of the above ground part and root system, increase the activity of root system and chlorophyll content, and increase the activities of nitrate reductase, superoxide dismutase, catalase and peroxidase of tobacco seedlings. The application of liquid organic carbon fertilizer can promote the growth and development of tobacco seedlings and enhance the stress resistance of tobacco seedlings, which is beneficial for promoting the growth and development of tobacco seedlings in south rice-tobacco area.