Obtaining three-dimensional ice shape data on the surface of the model in a low-temperature icing wind tunnel test is beneficial to analyze the effect of icing on the aerodynamic characteristics of the model and provides a basis for optimizing the model's anti-icing design. Due to the low-temperature environment of the low-temperature icing wind tunnel site, the core components of the existing visual measurement methods are difficult to work stably, and after the test, the temperature of the wind tunnel site will rise and the effective measurement time will be short. Therefore, ice shape measurement is facing great challenges. To this end, a low temperature protection system combined with thermal balance and external insulation was first designed to ensure that the core components in the equipment work at an appropriate temperature. Based on this, an ice type combining projection acceleration and low temperature protection was proposed. The fast three-dimensional measurement method, through the cooperation of the light source and the micromirror, to complete the two-stage exposure to achieve gray-scale recombination, which reduces the total flip period of the micromirror when projecting the image and improves the measurement speed. The experimental results prove that this method can realize stable and fast three-dimensional measurement of ice shape under the low temperature environment of -20℃．