In order to realize the transformation from qualitative research to quantitative research of electroless plating, computer simulation technology has been applied in the characteristic analysis of electroless plating metals. This paper adopts the statistical simulation method, takes the process of atomic deposition in amorphous electroless nickel-phosphorus plating as the research object, establishes a computer simulation model to simulate the migration and deposition of adatoms, and analyzes its influence on the microscopic pores of the coating. The research results show that there is a negative correlation between the migration probability and migration distance of the adatoms and the microscopic porosity of the coating. As the migration probability and migration distance increase, the probability of atoms filling the pores is larger, and the pores of the coating are smaller and the quality is higher. The computer simulation study in this paper is an effective supplement to the study of the deposition process of electroless plating, and it provides a theoretical basis for the study of the microstructure of metal coating.