According to airworthiness standards, the windshield surface should avoid icing to ensure the pilot's visual field. A reasonable heating power should be determined to prevent windshield icing. The convective heat transfer (HTC) is critical factor to affect heating power setting. For obtaining more accurate HTC, a low velocity wind test has been performed in this paper. And a CFD model has been built as same with test condition to calculate HTC. Comparing and analysis have also been done for finding a reasonable HTC modification method. In theend, the modification method has been used for the other cases.