It will occur a collision between the oil droplet and oil film on the wall, which affects the lubrication of bearing cavities and the heat transfer. In this paper, the high-speed camera is utilized to make the visualization research for the phenomenon of the oil droplet impacting the oil film on the wall. Furthermore, the form and dynamics of the oil droplet are investigated by changing the roughness of the wall and Weber number. The experimental results indicate that the morphology during impact can be divided into four modes according the relationship between non-dimensional roughness of the wall and Weber number. Additionally, the spatter phenomenon is a result under the combined action of K-H instability and P-R instability. Moreover, increases in the non-dimensional roughness and the Weber number affect the stability of crown margin, which will lead to severe the splash phenomenon. Therefore, it is concluded that the evolution and the spatter of the coronal structure are closely related to the roughness and the Weber number.