Visible light communication (VLC) is a wireless light communication technology.It is a hot topic in wireless communication research area.In this paper,VLC is used to research and design a wireless door control system.A light key and a light lock are made.Photoelectric conversion characteristics of LED and PD in me dium frequency and high frequency are analyzed.According to the analysis,the TX,RX,modem,code and s ystem control core are programmed.The system works under 10kHz on-off keying non-return to zero (OOK -NRZ) white light.It is of stability,electr omagnetic interference resistance,safty and low power.It has a good application value.