Abstract: This paper established optical propagation tracing mathematical model based on geometrical optics and parabolic approximation method, extracting maximum inter-vision ranges (MIVR) to denote the absolute detection range limit imposed by refraction for a given sensor and target height, determining the appearance mechanism of mirage. When wind speed is constant, MIVR decreases with the increase of air-sea difference in temperature (ASTD); but MIVR decreases with the increase of wind speed under the constant ASTD; the MIVR decreases with ASTD increasing, the corresponding relationships of MIVR and the height position is a standard straight line, and MIVR reduces with the height parameter decreasing; the accuracy of MIVR is better.