The invention discloses a building construction method. A construction method of a PCF plate provided with thermal insulation connection pieces comprises the following steps: installing an external wall steel reinforcement mesh in a prefabricated die; installing the thermal insulation connection pieces, concretely, the multiple thermal insulation connection pieces are arranged on the external wall steel reinforcement mesh, the thermal insulation connection pieces are arranged to be perpendicular to the steel reinforcement mesh plane, and multiple steel reinforcements penetrate through steel reinforcement connection holes in the thermal insulation connection pieces and fixed to the external wall steel reinforcement mesh; casting external wall concrete; paving a thermal insulation layer; and performing demoulding on the external wall, and installing the external wall provided with the thermal insulation layer and an inner wall in a combining way. According to the method, the novel thermal insulation connection piece structure is adopted, and the steel reinforcements which penetrate through the steel reinforcement connection holes in the thermal insulation connection pieces are connected with the steel reinforcement mesh, thus the whole-plane connection way is formed, the traditional point connection way is changed, the load on the plane of the prefabricated external wall board can be borne, the structure is stable and reliable, the forming quality of the PCF plate is improved, and the use safety is guaranteed.