Accurate azimuth measurement by laser detectors is a necessary condition for the seeker to guide towards the targetbut there is few theoretical research on the measurement accuracyso this paper studies the angular measurement accuracy of laser seeker.Firstlyan atmospheric transmission model of the guidance laser is establishedand it is verified that the light spot of the guidance signal received by laser detectors is uniform.Thenbased on the basic principles of azimuth detection by laser detectorsthe relationship between azimuth detection accuracy and three factorsi.e.the radius of the light spotthe position of the spots center and Signal-to-Noise Ratio (SNR)is deduced.Finallythe influence of different factors on azimuth detection accuracy is analyzed through simulation.The results show that angular measurement accuracy of the seeker can be improved by the following four methodsi.e.reducing the radius of the light spotshortening the distance between the centroid of the light spot and the center of the photosensitive surfaceincreasing the focal length of the detectors optical systemand increasing the SNR.