The invention relates to a preparation method for a floor and especially to a floor made of PVC. The objective of the invention is to provide a preparation method for a PVC floor, and the method enables the floor to have a higher density and stronger wear resistance through double calendaring. To fulfill the objective, the invention is characterized by comprising the following steps: 1, PVC granulation, wherein, corresponding raw materials are put into a high speed mixer according to a formula; 2, calendering molding, wherein, PVC particles of different colors are evenly mixed in a mixer according to a formula for design and color; 3, plasticization under heating, wherein, products obtained in the previous step enter into an electrically heating baking oven so as to allow materials to be plasticized under heating; 4, secondary calendaring, wherein, products obtained in the previous step are subjected to calendering extrusion molding so as to further adjust the thickness of the products; 5, last-stage treatment. The floor prepared in the invention has a longer service life, clear and natural patterns, a natural marble texture and a beautiful and elegant appearance, and is more applicable to public places having a great visitor flow rate, e.g., hospitals, airports, subways, large-scale markets, etc.