The atmospheric coherent laser communication technology has developed to the stage of practical deployment in the engineering terminals, but its theory is far away from perfect. The theory of atmospheric coherent laser communication and its relating research on adaptive optics and atmospheric scintillation are reviewed and analyzed. The precise analyses for the random process of beam perturbation and adaptive optical phase correction in atmospheric turbulence are the main challenges in completing the theory of coherent laser communication, and the probability method should be adopted in related research. At present, the basic framework of probabilistic analysis of adaptive optical phase correction has been formed, and the concept of scintillation for atmospheric coherent laser communication must be extended to include the variations of speckle and intensity, which should be investigated more fundamentally in future.