In order to meet the real-time requirement of the polarized light positioning system, the polarized light positioning system based on STM32 is designed, which achieves the synchronization of polarization azimuth data acquisition, reduces the complexity of the system data bus and the complexity of personal computer data receiving, and solves the problem of double-solution of solar altitude angle and azimuth. Firstly, based on the principle of polarized light positioning, four polarization azimuth acquisition modules are designed to get the polarization azimuth of the four directions in the sky, and the error of every module is under ±0.2°. Then, the sun vector judgment module is designed to solve the problem of 180° double-solution of solar altitude angle and azimuth, which results from the polarization vector. The experiments show that the polarized light positioning system can obtain the correct solar altitude angle and azimuth, and it is suitable for daytime. The maximum errors of longitude and latitude are ±1° and ±1.5° respectively in the experiment of about 55 minutes. The polarized light positioning system meets the requirements of real-time with a stable positioning accuracy, so it can be applied to the actual positioning.