This study investigated the effect of atmospheric turbulence on laser communication systems and proposed a communication detection and reception method based on closed-loop regulation of the APD gain factor. Building a wireless laser communication experiment verifies that the APD gain closed-loop regulation method significantly improves the system performance under the turbulence fading channel. The above experiments show that the APD gain control can effectively suppress the optical power fluctuations generated by atmospheric turbulence jitter; thus, significantly improving the communication performance. Under weak turbulence conditions, the power spectrum curve with AGC is more consistent with the 5/3 power-law spectrum. The variance of light intensity flicker is reduced from 0.057 to 0.023; the system R_BE is reduced from 1.75×10^-8 to 3.99×10^-10, a reduction of two orders of magnitude. Finally, the turbulence intensity and corresponding system average R_BE variation curves under different periods are calculated. This shows that the adaptive gain control algorithm effectively suppresses turbulence-induced signal power fluctuations and achieves high interference immunity for wireless laser communication.