The invention relates to a polyvinyl chloride/chlorinated polyvinyl chloride skin foamed sheet and a preparation method thereof, and the polyvinyl chloride/chlorinated polyvinyl chloride skin foamed sheet comprises the following materials in parts by weight: 60-90 parts of polyvinyl chloride, 10-40 parts of chlorinated polyvinyl chloride, 2.8-7 parts of stabilizer, 3-5 parts of foam regulator, 1-3 parts of foam nucleating agent, 0.5-2 parts of foaming agent, 0.6-1.5 parts of external lubricant, 0.5-1 part of internal lubricant, 0.5-2 parts of processing aids, 0.05-0.5 part of antioxidant and no more than 30 parts of filler. The preparation method is as follows: adding all the materials into a high-speed stirring machine, and mixing uniformly; heating to 90-120 DEG C, and carrying out heat preservation for more than 10 minutes; placing into a cold mixing machine, cooling down to 25-45 DEG C, tapping into a storage bin, extruding a foaming material through an extruder, and further carrying out vacuum shaping, cooling molding and edge trimming and finishing; and finally carrying out cutting and packaging according to the required length. The product has high surface hardness and great strength, is less prone to deformation, easy for processing, reasonable in manufacturing process, low in cost, good in quality and high in efficiency and has extensive popularization value and good economic and social benefits.