The invention relates to a synthetic resin and back coating liquid prepared from the same. The back coating liquid comprises the following components in percentage by weight: 0.5 to 5 percent of synthetic resin, 0.05 to 0.5 percent of curing agent, 3 to 10 percent of organic solvent 2 and 85 to 95 percent of diluent. In addition, the invention also discloses a preparation method of the back coating liquid, which has the characteristics of simple and convenient operation, mild condition and the like. The back coating liquid prepared by the method can resist the temperature of between 380 and 400 DEG C, and has the high lubricating property; the dynamic frictional factor of the back coating liquid is less than 0.2, and the static frictional factor is less than 0.3; and the back coating liquid can be widely applied to back coating of products such as hot code printing cingula, hot code printing thermal transfer ribbons, strip cingula and the like in the hot stamping industry.