The invention discloses a waterproof and wear-resistant composite paper pallet and a preparation method thereof. The waterproof and wear-resistant composite paper pallet is formed by compounding processing of a paper pallet with wear resistant fiber, an adhesive, polysiloxane resin, and nano-calcium carbonate. Specifically, the adhesive is prepared from the following raw materials by weight part: 15-30 parts of sodium carboxymethylcellulose, 5-10 parts of rosin glycerol ester, 10-20 parts of an aluminate coupling agent, 4-12 parts of polyurethane, 5-15 parts of phenolic resin, 3-8 parts of polystyrene, and 40-60 parts of a 45%-75% ethanol solution. According to the preparation method of the composite paper pallet, on the basis of the traditional paper pallet, the wear resistant fiber and nano-calcium carbonate are closely combined together through the adhesive, then a layer of polysiloxane resin is sprayed to the outer surface of the composite paper pallet, so that the prepared composite paper pallet has excellent wear resistance and waterproof performance, and significantly increased compressive strength. With a simple production process, the waterproof and wear-resistant composite paper pallet has very good economic value.