To address the issues of poor real-time performance and unsatisfied accuracy in attitude determination systems with large time delay,an algorithm is proposed for compensating the time delay in monocular vision.Taking the air-floating platform as the application background,a combined attitude determination system of “monocular vision+MEMS gyroscope” is designed to acquire the attitude information.The time-delay issue in monocular vision is compensated by integrating the gyroscope to correct the attitude quaternion,and a compensation model is established to analyze the main components of the time-delay error in monocular vision.The Extended Kalman Filter (EKF) is employed to process the angular velocity and the compensated attitude quaternion in real time,thus to obtain the attitude information of the lightweight air floating platform.Finally,the rationality and advantages of the attitude determination system design are validated through physical simulations.The experimental results demonstrate that the system design is reasonable and capable of providing high-precision attitude information,which can meet the requirements of the air-floating platform.