The invention discloses a circular polarized antenna with a wide wave beam width and a small size. The antenna comprises a square paster; two notch grooves of an open circuit of a terminal are arranged on the square paster, wherein the two notch grooves are mutually orthogonal; the paster is fixed on a square grounding reflecting surface by a coaxial line. And four short-circuit columns of the open circuit of the terminal are arranged on the reflecting surface, so that the size of the reflecting surface is reduced. According to the invention, a signal feeding technology is utilized to excite the two orthogonal notch grooves to work in a circular polarization mode. According to the invention, an impedance bandwidth reaches 19%, wherein a standing-wave ratio is less than 2; and a 3d axial ratio bandwidth reaches 3.8%. In an axial ratio bandwidth, a 3d B wave beam width reaches a value by adding 101.4 degrees with 1.4 degrees or subtracting the 1.4 degrees from the 101.4 degrees as well as a gain reaches a value by adding 5.76dBi with 0.18dBi or subtracting the 0.18dBi from the 5.76dBi. The circular polarized antenna has advantages of compact antenna dimension, light weight, low cost and easy manufacture. Especially, the circular polarized antenna has advantages of good impedance bandwidth, wide radiation wave beam, and high gain. Therefore, the circular polarized antenna can be widely applied to satellite communication and traffic navigation.