The underwater and aerial inter-communication is realized with laser scanning technology. The construction and the principle of the two-dimensional galvanometric scanner laser scanning system are theoretically described. The methods to effectively control the laser beam with bunch expanding devices and the galvanometric scanner system in the visible range and finish the scanning of the area of the goal underwater and in the air in the underwater optical communication system. And the relation among the scanning way, the scanning range and the speed of scanning is referred mainly. With the systematical simulated experiment, the realizing way and the related experimental data are obtained. Based on the light reflection principle, the mathematical relation of the mechanical angle and the optical angle is emphasized. With the experiment, the approximate calculation formulas about the rectangular scanning and the rectangular scanning area are derived. The experiment proves the feasibility of the communication method and the scanning technology, which establish the foundation for the forthcoming research and practical application.