The invention belongs to the technical field of optical display and relates to a visual optical system parallax calculation algorithm. The algorithm is mainly composed of an interactive interface setting module, a computational mesh module, a light trace direction judging module, a parallax calculation convergence speed control module, a parallax calculation precision control module, a data induction and analysis module, a graphical output module and so on, wherein the ray tracing direction judging module determines the ray tracing direction according to the trial and error method, then, according to the distance between the target point and the starting point, the convergence speed of the single calculation is determined by the parallax convergence speed control module. Through many iterative calculations, the tracking point gradually approaches to the target point, and finally the target point is determined by the parallax precision control module. As a visual optical system parallaxcalculation algorithm, that invention can realize one-key simulation analysis and graphic output of all field parallax in the entire pupil exit range of the visual optical system, has high parallax calculation efficiency and adjustable calculation precision, and provides an efficient and high-precision simulation analysis method for real-time calculation of the visual optical system parallax.