The purpose of this paper is to study the methods that retrieving carbon dioxide from tail gas of hydrogen plant and the use the recovered carbon dioxide into food preservation, which can turn waste into treasure and create economic benefits.The carbon dioxide in the tail gas of hydrogen plant is purified by TPCR method. Then fresh keeping experiment of litchi, pork and leek is carried out to analyze the fresh-keeping situation of samples under different conditions. After that, the volume fraction of carbon dioxide in the tail gas is increased to 99.9%. On the second day of observation, litchi in the fresh-keeping experiment control group began to appear browning and the pork also had a bad smell, and the leek was wilting and turning yellow. There was also slight water-loss in the refrigerated group, but the samples in the dry ice group were all good. On the seventh day of observation, litchi in dry ice group had the lowest browning index which was only 0.7. The weight loss rates of litchi and leek were only 2.2% and 4.15%.The recovery of carbon dioxide from tail gas can not only reduce the amount of carbon dioxide in the atmosphere, but also can be widely used in food preservation to extend the storage life of food and achieve green and sustainable development, which is of great significance to the national economy and the people's livelihood.