The invention relates to a food information tracing method based on a relational database. The method comprises the following steps of: collecting information of food in the production, storage, transportation and selling processes; associating the information with the food, and then storing the information into relevant nodes; storing enterprises through which the food sequentially passes in the circulation process into a tracing path table so as to form a food tracing tree diagram with the path tracing function; and then, tracking or tracing the relevant information of certain food according to the food tracing tree diagram. The food information tracing method has the advantages that the tree diagram in the food tracing process is built; if the information of the food is increased, information increased in the links can be supplemented into relevant nodes, so that the information storage becomes reasonable; great convenience is brought for the information query and retrieval of relevant food in the whole production and circulation processes through the building of the tree diagram in the food tracing process; the links with problems can be found in time through tracing; and the food safety is further guaranteed.