The GCr15 high carbon steel powder prepared by plasma rotating electrode was used as the experimental raw material and prepared by selective laser melting (SLM). The effects of laser power, scanning speed, and volume energy density on the formability of GCr15 and the structure transformation after forming during SLM forming process were studied. Experimental results show that the laser power, scanning speed, volume energy density, and relative density are in a linear relationship within the adjustable range of parameters. It can be seen from the energy density curve that the power has a greater effect on the relative density than the scanning speed. In the case of low power, the relationship between the power and the relative density will be distorted. At the same time, the microstructure of GCr15 bearing steel prepared by selective laser melting is small and uniform mainly consisting of coarse needle-like martensite and retained austenite. With the increase of energy density, the content of retained austenite increases.