The relationship of the visible light distribution and the positioning function of the indoor ID positioning system was studied. An asynchronous positioning system based on visible light communication was constructed. Through simulation and experiment, the positioning range and bit error rate of the system were measured. The result shows that, the light distribution of the actual model can be approached by the Matlab software. After that, a 50 cm×50 cm×50 cm prototyping was built. Inside the optical boundary, the communication and positioning function can be achieved. And around the optical boundary, the bit error rate of the system rose. When the SNR was 25 dB, an 8 cm signal blind zone was shown around the optical boundary. The zone can be reduced by improving the SNR of the positioning system.