Building house outer wall waterproof coating construction method

The invention relates to the technical field of building wall construction, and discloses a building house outer wall waterproof coating construction method which comprises the following steps: S1, base layer treatment; and S2, the wall is wetted. Foreign matters or loose parts are secondarily removed through base layer treatment and wetting, the bonding strength between mortar and a putty layer and the wall is improved by wetting the wall, the local part of the concrete wall is repaired and leveled through marking measurement, the bonding stability of the repaired position is improved in cooperation with a first anti-cracking grid and a second anti-cracking grid, and consumables are saved. Original colors of a concrete wall surface are greatly utilized through integral or local color matching, colors of repaired and leveled parts are uniform and consistent, the bonding strength between repairing mortar and a putty layer and a wall body is improved by permeating primer into a material, and the water absorptio