Indoor visible light communication technology is based on white light-emitting diode (LED) light source of optical wireless communication technology. At the airport, hospitals and other places where there are strict limits of electromagnetic interference, the technology can replace the radio communications, which has profound application prospects. Considering the influence of the wall reflections during the indoor visible light transmission, the indoor visible light illumination distribution was obtained by experimental measurements in a room of 4.0 m×4.0 m×2.8 m. It can be concluded that the light source of the optical signal reflected by the wall produces severe multipath effects, and then limits the communication rate. The experimental verification of indoor visible light distribution and simulation research was carried out. Moreover, the results of the experiment nearly agree with the theoretical simulation.