Visible light communication (VLC), as a wireless communication method, has attracted wide attention. The popularity of GaN-based light emitting diode (LED) has also laid a solid foundation for the application of VLC. LED as the light source of VLC, its modulation bandwidth directly determines the speed of communication. This paper reviews the research progress of modulation bandwidth improvement schemes for GaN LED transmitters, covering all aspects from epitaxial to device. Epitaxial methods include c-polar epitaxial optimization, non / semi-polar epitaxial growth and chip schemes, such as micro LED, nano LED, resonant cavity LED (RC-LED), plasma exciton and supercavity LED. In terms of white LED, the methods to solve the slow Stokes transmission and long carrier lifetime of traditional phosphors are reviewed, including new color conversion layer materials (CCMs) and new energy transmission routes. This review promotes the development of GaN-based LED as a high-speed VLC transmitter.