The invention discloses an environment-friendly waterproof building outer wall construction method. The environment-friendly waterproof building outer wall construction method comprises the followingsteps that a, 
rust removal is conducted on exposed 
metal of an outer wall body, a steel 
shovel is used for flatly shoveling a protruding part of the wall body, a 
brush is used for sweeping dust and 
powder, finally, high-pressure water is utilized for conducting clean flushing, and standing airing is conducted; b, 1:3 
cement mortar with the thickness being 15 mm is used for screeding of the surfaceof the outer wall body, and a leveling layer is formed; c, the leveling layer is coated with a 
polymer cement waterproof 
coating with the thickness being 1.0-1.2 mm, and then a 
polymer waterproof 
mortar layer with the thickness being 3 mm is used for leveling and covering; d, the surface of an 
asbestos board is coated with a 
polyurethane bonding agent, and the 
asbestos board is glued to the 
polymer waterproof 
mortar layer; e, the other face of the 
asbestos board is provided with an anti-
cracking waterproof mortar layer with the thickness being 6-8 mm, pressing of 
glass fiber gridding cloth isconducted, and then coverage of a layer of anti-
cracking waterproof mortar layer with the thickness being 6-8 mm is conducted; and f, finally, the surface of the 
protection layer is provided with a facing layer. According to the technical scheme, the waterproof performance of the structure is enhanced, and the waterproof crack resisting performance of the outer side of a heat preservation layer is guaranteed.