Abstract: By releasing easily ionized metals in the ionosphere, artificial space plasma clouds can be generated to form an artificial channel for radio waves to propagate beyond visual distance. Based on the artificial space plasma cloud channel, it is helpful to solve the problem of the shortwave system depends on the ionosphere state, and improve the anti-interference ability of the shortwave communication system. It can also break through the natural conditions of the ionosphere, expand the electromagnetic frequency band range of over-the-horizon transmission, and realize the new quality of electromagnetic propagation. In this paper, the physical and chemical processes of Sm vapor in the ionosphere are studied. The physical model of Sm release in the ionosphere is established, and the space-time evolution of the plasma cloud is simulated. The beyond-line-of-sight wave characteristics of space plasma cloud are studied by ray tracing method, and the beyond-line-of-sight scattering model of space plasma cloud is established. According to the electron density intensity and distribution characteristics of the artificial plasma cloud, the geometric diffraction theory is introduced to calculate the scattering field of the artificial plasma cloud, and the spatial-temporal variation characteristics of the scattering field of the plasma cloud are studied. The study lays foundation for the research of artificial space plasma cloud beyond over-the-horizon information transmission technology.