Optical camera communication (OCC) is a new wireless optical communication technology,which uses the rolling shutter working mode of mobile phone camera to shoot fast flashing light emitting diode (LED), receives the stripe image separated by light and dark, and decodes and recovers the image to realize data communication. However, the fluctuation of gray value in the process of data transmission will affect the bit error rate (BER), transmission distance, and data rate in the process of communication. A new demodulation scheme of OCC signal is proposed. The adaptive image enhancement algorithm based on expansion corrosion is used to eliminate the overall fluctuation of gray value, and the expansion algorithm is used to eliminate the local fluctuation of gray value. It is comprehensively processed from the overall and local aspects to eliminate the fluctuation of gray value to the greatest extent and improve the accuracy of judgment, so as to improve the communication performance of the system. To verify the performance of the proposed scheme, BER under different transmission distance and data rate is evaluated. The experimental results show that the average BER of the proposed scheme is two orders of magnitude lower than that of the traditional signal demodulation algorithm.