The propagation path of wireless wave is often affected by many factors. In actual military operations, more and more people have focused on the influence of the air refraction, especially evaporation duct. The reason is that evaporation duct could trap electromagnetic wave, make the path of the wireless wave longer or shorter. At present, an evaporation duct model is still the best tool to evaluate an evaporation duct. In this paper, one kind of evaporation duct models called MGB model is introduced, and we use the experiment data to test the applicability of the two MGB evaporation duct models. The conclusion can offer some help for realizing MGB model.