Based on developing process of aero-optics, the background of the subject is introduced. The definition, intension, research object, research methods of the subject are proposed. The research contents are described, which include mechanism, calibration methods, calibration tests for aero-optic effects and optic window of the hypersonic aircraft. The theoretical research, engineering modeling, testing principle and testing methods in China are described in detail. Some representative results are given. At last, the application prospects and research tendency of the subject are suggested.