The head-up display HUD has gradually become an important interactive interface connecting the driver, vehicle status, and road environment from the window displaying basic information such as vehicle speed and navigation. At the same time, the HUD carries more and more information, the information level is not clear, the focus is not prominent, it is difficult to identify in a complex environment, etc., which affects the driver's rapid access to key information. How to enable users to "see clearly, understand and use well" in complex driving scenarios has become a common concern for the global smart car industry. In order to solve these problems, Changan Motor has completed a total of seven proposals over a period of three years, promoting the formation of the ITU-T F.749.20 international standard, which was officially released in the International Telecommunication Union (ITU) recently. The release of this standard provides an international standard reference for the design and application of smart car HUDs worldwide. During the development of the standard, Changan Automobile Human Factors Engineering Laboratory repeatedly verified the HUD scheme from the user's real driving experience, relying on eye movement, EEG, skin electricity and other research equipment to simulate typical scenarios such as high-speed driving, urban roads, and entrance and exit tunnels. By translating users' true feelings into quantifiable and landable design requirements, Changan Automobile has promoted HUD from simply focusing on display effects to further balancing safety, efficiency and comfortable human experience. At present, the relevant research results have been applied to Changan Qiyuan A07, Changan Qiyuan A06, Deep Blue S05, Mazda EZ-60 and other main models. By optimizing the information layout, display level and readability in complex scenarios, Changan Automobile allows drivers to obtain key information such as speed, navigation, speed limit, driving assistance and safety reminders more intuitively, and truly translates the standard research results into user-perceived safety and experience enhancement. (Compiled by Qin Chao, Automobile House).