The invention provides a middle material layer of an environment-friendly plastic floor and the plastic floor. The middle material layer of the environment-friendly plastic floor is prepared from the following raw materials in parts by weight: 100-105 parts of polyvinyl chloride, 35-40 parts of biomass vegetable oil, 1.2-2.2 parts of stabilizer, 0.2-0.5 part of carbon black and 450-470 parts of calcium carbonate. In the middle material layer of the environment-friendly plastic floor and the plastic floor, the biomass vegetable oil is used as plasticizer; the biomass vegetable oil and the polyvinyl chloride have favorable compatibility; and the biomass vegetable oil has favorable flexibility, light resistance and weather resistance, and is non-toxic and easy to degrade. Thus, the prepared middle material layer and plastic floor are safe, environment-friendly; and the biomass vegetable oil is low in cost, so that the material cost can be effectively controlled.