A multi-frequency antenna comprises a feed-in end, a first ground connection part, a second ground connection part, a first emission arm, a second emission arm, a third emission part and a fourth emission part, wherein, the first ground connection part and the second ground connection part are adjacently arranged at two sides of the feed-in end; the two ends of the first emission arm are respectively fixedly connected on the first ground connection part and the feed-in end; the second emission arm and the third emission arm are formed by extending outward the first emission arm and share the feed-in end; one end of the fourth emission arm is fixedly connected on the second ground connection, and is formed by extending outward the second ground connection part. When the multi-frequency antenna is in work, the signal enters through the feed-in part and acquires transmission paths with different lengths along the first emission arm, the second emission arm, the third emission arm and thefourth emission arm and generates different signal current and resonant frequencies, thus ensuring that the multi-frequency antenna has multi-frequency operating characteristics.