The invention discloses a preparation method of an environment-friendly double-process mirror-surface crystal leather. The method includes: selecting polyester polyether copolymer copolymerization type polyurethane resin, pearl powder, pigment and dimethylformamide as the surface layer and bonding layer of a first dry process, and pasting a creaseless and elastic wet process synthesized leather semi-finished product, pressing pearlescent three-dimensional lines on a dry process semi-finished product by a cold-pressing technology, employing polyester polyether copolymerized high modulus polyurethane surface layer colorless slurry and a high solid two-liquid type polyurethane colorless slurry to conduct secondary dry process full dry pasting technology on mirror-surface release paper, and gluing the pearlescent line-embossed semi-finished product to obtain the environment-friendly double-process mirror-surface crystal leather. The environment-friendly double-process mirror-surface crystal leather prepared by the method provided by the invention has the advantages of crystal gloss, high transparency, bright and fashionable color, texture, smooth surface touch sense, three-dimensional lines, wearproof, scratch resistant and creaseless surface, and small DMF residual amount, and can reach the environmental protection requirements of the EU "regulation concerning the registration, evaluation, authorization and restriction of chemicals" REACH.