The invention discloses an ultrahigh-frequency RFID anti-metal tag antenna based on a microstrip structure. The antenna comprises a dielectric substrate and a radiation module arranged on the dielectric substrate, the dielectric substrate is a rectangular plate, and the radiation module is realized by adopting the microstrip structure. The radiation module comprises a radio frequency chip, a metal layer, a first rectangular groove, a second rectangular groove, a third rectangular groove, a first radiation unit and a second radiation unit, the first radiation unit and the second radiation unit are respectively composed of eight rectangular metal blocks, and the first radiation unit and the second radiation unit form a symmetrical oscillator antenna structure; and the first radiation unit and the second radiation unit form a U-shaped groove communicated with the first rectangular groove and the third rectangular groove, and a gap formed between the first radiation unit and the second radiation unit and a gap in the first radiation unit and the second radiation unit form an impedance adjusting structure. The antenna has the advantages of being long in reading distance, high in gain, small in size, simple in processing technology, low in cost and wide in frequency band.