Abstract: [Objectives] In order to effectively broaden the beam width of the 3dB axis ratio of Beidou antenna, a slotted laminated microstrip patch antenna loaded with parasitic elements is proposed.. [Methods] The Beidou dual frequency band feature is realized through a two-layer substrate structure. The bandwidth is widened by slotting. Circular polarized radiation is achieved by chamfering the edge of the patch. At the same time, L-shaped parasitic elements are loaded around the patch to broaden the 3dB axial ratio beam width of the antenna. [Results] The measured and simulated results are in good agreement. The relative bandwidth of the antenna in the Beidou B1 and B2 bands is 3% and 7.5%. The beam width of the 3dB axis ratio can reach 180 ° and 176 °, and the maximum gain can reach 6dBi. In the Beidou receiver test, the number of antenna satellites can reach more than 17, and the positioning accuracy is within meters. [Conclusions] It is a high-precision positioning dual band Beidou navigation antenna with wide axis ratio beam width. The research results can provide reference for the design of small Beidou navigation antenna.