The effects of the expansion angle of partially coherent Gaussian-Schell (GSM) beam on the receiving optical power are analyzed, numerical calculation and simulation are used in the laser extension angle and the receiving optical power of the laser communication link, and at the same time the influence of the beam′s expansion angle on the power of the laser communication link is analyzed quantitatively. The results show that, the receiving power of partially coherent GSM beam is inversely proportional to the beam waist radius, as well as the spatial coherent length and transmission distance. Besides it is proportional to the wavelength. Based on that, when comparing partially coherent GSM beams with coherent Gaussian beams, it turns out that the power loss of the partially GSM coherent light caused by beam expansion is less than coherent Gaussian light. Under the certain condition of initial parameters, the receiving power of partially coherent beam is completely 2.65 times larger than coherent beam.