The utility model discloses a helical antenna. The antenna comprises a printed circuit board and a radiation main body arranged above the printed circuit board, the radiation main body comprises at least one main spiral arm and at least one parasitic spiral arm, each main spiral arm corresponds to at least one parasitic spiral arm, and each main spiral arm and the corresponding parasitic spiral arm are arranged in parallel at intervals; wherein the first end of each main spiral arm is electrically connected with the first end of the corresponding parasitic spiral arm to form a feed output endof the spiral antenna; the second end of the main spiral arm and the second end of the parasitic spiral arm are both in floating connection; the length of each parasitic spiral arm is larger than thatof the main spiral arm corresponding to the parasitic spiral arm, and the helix angle of the portion, exceeding the main spiral arm, of each parasitic spiral arm is smaller than that of the portion,not exceeding the main spiral arm, of the parasitic spiral arm. According to the helical antenna, the frequency bandwidth can be expanded to 6%, and the structure of the helical antenna is more compact.