The steam generator is an important part of the nuclear power plant, and the corrugated plate separator plays the important role of drying steam in the steam generator to improve power generation efficiency and protect the safety of the system. The separation mechanism of the corrugated plate separator is relatively complicated. The droplets are moved by the drag force of the steam and gravity in the corrugated plate separator, and captured by the wall of the corrugated plate separator. When the velocity is increased, the inertial force of droplet is increased, so that the droplet is more easily captured by the wall of the corrugated plate separator, and the separation efficiency of the corrugated plate separator is increased. In this paper, the phenomenon of droplet impact on the inclined wall is studied by high-speed photography technology, and the cause and mechanism of the phenomenon are analyzed. By analyzing the spreading and splashing on the droplets impacting on the inclined wall, the relationship between the inclination angle of the droplet impacting on the inclined wall and the spreading is obtained, and the influence of droplets with different Weber numbers, and dry and wetted walls were analyzed, which provide a basis for the optimization of the corrugated plate separator.