The invention provides a vehicle trunk shelf device. The shelf device comprises a side enclosure plate assembly and a shelf assembly; the side enclosure plate assembly comprises a side enclosure platesupport, a rotating shaft adjusting button and an adjusting spring; a first groove, a second groove and an adjusting button telescopic groove are formed in the side enclosure plate support in the advancing direction of a vehicle; the adjusting spring is arranged on the rotating shaft adjusting button in a sleeving mode and is placed in the adjusting button telescopic groove; the shelf assembly comprises a shelf body, a first rotating shaft, a second rotating shaft and a reset spring; a rotating shaft groove is formed in the shelf body in the width direction of a vehicle body, and the reset spring sleeves the first rotating shaft and is placed in the rotating shaft groove; the second rotating shaft is fixedly connected with the shelf body which is arranged in parallel with the second rotating shaft; the first rotating shaft is embedded in the first groove, and the second rotating shaft is embedded in the second groove. Through independent rotation of the two rotating shafts, the purpose of bidirectionally opening the shelf is achieved, and passengers can conveniently take and place articles.