The traditional pure nickel coatings and the Ni-Co alloy coatings were prepared with the same parameters on the type 316L stainless steel substrates by utilizing two-ways pulse current electroplating method. And then, we used atomic force microscope (AFM) to observe their surface morphologies and structures and obtained their 3D images. The results of AFM showed that the Ni-Co alloy coating were superior to the traditional pure nickel coating on mechanical and tribological properties respects. For example, the surface of the Ni-Co alloy coating is smoother and even than that of the traditional pure nickel coating. Direct current (DC) and two-ways pulse current electroplating two methods were adopted respectively to prepare the Ni-Co alloy coatings. Followed we observed their surface morphologies by using AFM. The result showed that under the same experimental parameters the coating of the two-ways pulse current electroplating is superior to conventional DC electroplating coating in the surface morphology, grain size and microstructure and so on.