In order to study the influence of light intensity flicker on the visible light communication of light emitting diode (LED), based on the spatially incoherent monochromatic LED light source, the channel transmission characteristics of visible light communication under weak turbulence are theoretically studied, and the closed expression of light intensity scintillation coefficient of monochromatic LED visible light communication system is deduced. The system characteristics of LED and laser visible light communication under different factors are compared and analyzed. The simulation results show that the scintillation coefficient of LED visible light communication is smaller than that of laser visible light communication under weak turbulence, and the system bit error rate caused by turbulence disturbance is also lower. In addition, with the increase of light intensity flicker coefficient and average transmitted light power, the bit error rate gap between LED and laser visible light communication systems affected by turbulence is gradually increased.