VGA signal selection switching module and method applied to OSD menu

The invention discloses a VGA signal selection switching module and method applied to an OSD menu. The structure of the module comprises a Hsync and Vsync determination and generation module, a DA conversion module, and an RGB analog selection switch, wherein the Hsync and Vsync determination and generation module is used for the determination of Hsync and Vsync signals which are inputted from the outside or generated internally. The DA conversion module is used for converting a logically-generated OSD RGB signal into an analog signal. The RGB analog selection switch is used for selecting RGB signals of OSD RGB and external video stream, i.e., the OSD RGB signal. The selection switching method is achieved based on the module. Compared with the prior art, the module and method are high in compatibility, are flexible in design, are simple and convenient in enforcement, are wide in application prospect, are not limited by an external VGA signal source, can achieve the overlapped display of the OSD menu and an external VGA signal, and facilitate users' operation, are high in practicality, and are easy to popularize.