The present invention provides a method for sharing a graphics card among multiple Operation Systems (OSs) and a computer system. The method comprises: detecting a first GOS to be displayed, the first GOS being one of at least two GOSs; calling a correspondence table to determine a first display control register bank corresponding to the first GOS, the first display control register bank including display mode parameters therein; controlling the first display control register bank to connect to a display output port; and displaying the first GOS based on the display mode parameters. According to the inventive method and computer system, it is possible to achieve sharing of the graphics card among the multiple OSs and quick display of the GOS to be displayed, without simulating registers of the graphics card.