The invention discloses a wall construction method which comprises steps of preparing materials, mixing the materials, constructing a wall, molding a wall blank, plastering, constructing a wall, and coating the wall. The step of mixing the materials in the method is carried out in a mixing device, the mixing device is internally provided with a crude material baffle plate and a fine material baffle plate, a fine material is thrown out to the center of a cylinder by the fine material baffle plate in a rotation process, a crude material is thrown out to the edge of the cylinder by the crude material baffle plate, then the crude material and the fine material can be relatively uniformly mixed, uniform material mixing can be facilitated, and the quality of a wall can be improved.