Abstract: Aiming at the determination of the attitude of the moving carrier by the vehicle-mounted mobile measurement system, the attitude determination method of the vehicle-mounted Global Navigation Satellite System (GNSS) antenna array is studied, the attitude calculation formula of the direct method and the least square method is analyzed, and the GNSS is carried out. Antenna array vehicle experiment. In order to obtain the accuracy of the two attitude determination methods, the direct method and the least square method are used to calculate the attitude on the basis of different software positioning modes. The experimental and analysis results show that the accuracy of the four-antenna array least squares attitude determination is better than the three-antenna array direct method, and the reliability is higher; among all the combinations, the four-antenna array least squares attitude determination accuracy based on the moving-base positioning mode is the highest, its heading angle, pitch angle and roll angle accuracy can reach 0.066 0°, 0.168 4° and 0.267 8° respectively.