This paper introduces the systematic structure of embedded Linux framebuffer device driver, and gives a detailed analysis of the key data structures and writing method. Through the example of Linux framebuffer device driver based on ARM9-CPU S3C2440, implementation principle and development process of Linux framebuffer device driver based on Platform bus in the Linux2.6.33 kernel is analyzed. Finally, it gives the general methods about the access to framebuffer device by user-space application.