The invention relates to synthetic ester for rolling oil. The synthetic ester comprises tetrahydric acid ester which has a structure as shown in the formula (I), in the formula (I), A is substituted or unsubstitutedalkyl, and at least one of B1, B2, B3 and B4 is a group containing a polyether structure. The polyether structure is introduced in the synthetic ester for the rolling oil, the tetrahydric acid ester has properties of a nonionic emulsifier, and the synthetic ester has good permeability, self-emulsifying performance and dispersing performance. When the synthetic ester is used for the rolling oil, cleaning of a rolling machine and a plate surface is facilitated by the permeability and the dispersing performance; in a high-temperature rolling process, stability of emulsion of the rolling oil can be maintained by the self-emulsifying performance, concentration response is good, oil slick of emulsion is less, the service life of the emulsion is prolonged, oil consumption is low, and therefore, the synthetic ester is easy to manage. The synthetic ester is the tetrahydric acid ester, has high-temperature stability, cannot be decomposed easily, cannot produce a large amount of smoke, and is environmentally friendly.