The invention discloses a gasoline identifier for distinguishing a gasoline octane number in oil supply quality management. The gasoline identifier is used for being pasted on a container for holding gasoline and is detected by a detecting instrument to transmit a signal related to the gasoline octane number. The gasoline identifier is characterized by comprising a piezoelectric plate, an input interdigital transducer and an output interdigital transducer, wherein the input interdigital transducer is arranged on the surface of the piezoelectric plate; the output interdigital transducer is arranged on the surface, which is identical with that of the input interdigital transducer, of the piezoelectric plate, is arranged opposite to the input interdigital transducer and is used for receiving a sound signal transmitted by the input interdigital transducer. By application of the gasoline identifier disclosed by the invention, the octane number (gasoline brand) of commercially available final gasoline can be quickly, simply and conveniently detected, and rapid oil detection is provided for occasions and systems such as fueling stations and logistic supply of military oil products; the gasoline identifier is especially suitable for rapid detection.