The invention discloses a thermoplastic elastomer. The thermoplastic elastomer contains the following components in parts by weight: 40-90 parts of matrix resin, 5-30 parts of a softening plasticizer, 3-15 parts of a mineral filling agent, 3-15 parts of a compatilizer, 0.2-2 parts of a lubricating agent and 0.2-0.5 part of a stabilizer. The invention further discloses a preparation method of the thermoplastic elastomer. The preparation method comprises the following steps: sequentially adding the matrix resin, the softening plasticizer, the mineral filling agent, the compatilizer, the lubricating agent and the stabilizer into a high-speed mixer, and uniformly mixing, so as to obtain a mixture; and putting the mixture into a double-screw extruder, extruding at 170-195 DEG C, and sequentially carrying out bar drawing, water tank cooling and granulation, so as to obtain the thermoplastic elastomer. A wood-plastic floor is prepared from the thermoplastic elastomer disclosed by the invention. The thermoplastic elastomer provided by the invention has the advantages of strong coating cohesive force, soft texture, wear resistance, light specific gravity and the like; and furthermore, the prepared wood-plastic floor coated with the thermoplastic elastomer has the functions of shock absorption, skid prevention and noise reduction.