The cloud-channel transmission characteristics of given wavelength signal are analyzed by setting up a new ground-to-ground cloud-scattering model. By simulation, the predicted path loss of three typical clouds under given transmission configurations are expatiated theoretically and quantitatively. Furthermore, the effects of the path loss caused by elevation angles and transmitting beam width divergence are analyzed independently. The results show that the best communication range decreases when the elevation angles increase on the condition that field of view is fixed. When small transmitting beam width divergence is considered(less than 1°), the transmitting elevation angle must be adjusted so as to the facula on the bottom of cloud produced by the transmitting source light locating on the top of the receiver, but when transmitting beam width divergence is large relatively, elevation angles should be adjusted in order to make the first effective scattering volume maximal. The field cloud-scattering path losses on the communication range of 11.7 km under different receiving elevation angles were obtained by experiments carried in Nanjing, and the above analysis was validated by data. The conclusions obtained in this paper are wavelength-relevant, laser diode with 808 nm and 620 nm are chosen as the transmitting source light.