The invention belongs to constructional methods for architectural decoration, which is, in particular, a constructional method for pillars and architrave cornices. Prior constructional method is to fabricate the Corinthian pillars and the architrave cornices separately and to splice them during on-site installation, wherein the Corinthian pillars are cast in cement and the pillars are holistically sculpted from natural stone. Such constructional method has the disadvantages of great difficulties in sculpting and processing the pillars, inconvenience for transportation due to the heavy weight and huge volume of the pillars, high constructional cost, poor controllability during the whole construction process, severely-impacted constructional quality and delayed construction progress. Aimingto address the defects with prior constructional method, the invention provides a technical scheme for construction that all sections except the pillar heads and piers are uniformly assembled on the installation site and then cast in vertical dies. By this method, the pillars and architrave cornices are shaped at the same time, thus facilitating construction, eliminating the need to transport thepillars separately, greatly reducing the cost compared with that of pillars sculpted with stone, effectively control the construction progress and enhancing the constructional quality.