The present invention provides a method for preparing a vinyl chloride-based polymer, the method including (1) polymerizing a vinyl chloride-based monomer in the presence of a vinyl chloride-based first seed particle, a vinyl chloride-based second seed particle, and an emulsifier and (2) separating, after the polymerizing, a first vinyl chloride-based polymer and a second vinyl chloride-based polymer which are in a particulate form, wherein the separated first vinyl chloride-based polymer is dried using a fluid bed dryer (FBD), and the first vinyl chloride-based polymer has a smaller average particle diameter (D50) than the second vinyl chloride-based polymer, and two kinds of polymers having different physical properties may be prepared through a single manufacturing process.