The invention discloses an environment-friendly PVC (polyvinyl chloride) wood-plastic foamed board material and a preparation method thereof, and relates to the technical field of a PVC wood-plastic material. The foamed board material is prepared from the following raw materials: polyvinyl chloride, modified rice husk powder, modified saw dust, kaolin, pyrophyllite powder, light calcium carbonate,styrene-acrylic emulsion, benzoyl peroxide, polybutanediol carbonate, a foaming agent, a processing modifier ACR, an adhesion aid and an initiator. The preparation method comprises the steps of mixing the raw materials, extruding and shaping. The PVC wood-plastic foamed board material has an integrated and beautiful appearance, high dimensional stability, light weight and high strength, has the advantages of high sound-insulating and heat-insulating properties, high flame-retardant and waterproof grade, excellent mildewproof and insect-preventing properties and the like, and is long in service life, wide in application field, environment-friendly and suitable for popularization and application.