The distribution of laser diode beam is described in the form of mixed Hermite-Gaussian mode. We study the relationship between beam waist width and beam propagation factor by using the beam second-order term matrix. The influences of generalized exponent and anisotropy coefficient on beam propagation factor are analyzed. Results show that，for different turbulence intensity, there are different beam widths which make the beam propagation factor minimum. In addition, the increasing of anisotropy coefficient of atmospheric turbulence model reduces the influence of atmospheric turbulence on beam propagation factor. Simulation for the two-dimensional beam quality trace illustrates that the influence of anisotropy coefficient on beam propagation factor trace will be more obvious when the propagation distance is increasing. The result may help the development of atmospheric laser beam propagation theory and has important significance in applications of atmospheric optical communication and lidar detection.