The invention discloses a BIM-technology-based construction method for a 90-DEG mouth-to-mouth vaulting mould used for flues of a coke oven. The construction method comprises the following steps: step 1, creating a parameterized 90-DEG mouth-to-mouth vaulting mould module for the flues of the coke oven and a three-dimensional 90-DEG mouth-to-mouth vaulting mould model according to design paper; step 2, numbering members of the three-dimensional model, creating and outputting a list of the members and carrying out modularization prefabrication and processing; step 3, transporting the processed members to a construction site and re-checking the sizes of the members according to the three-dimensional model; and step 4, assembling the members according to the three-dimensional model and building the 90-DEG mouth-to-mouth vaulting mould for the flues of the coke oven. According to the invention, the three-dimensional 90-DEG mouth-to-mouth vaulting mould model is established based on the BIM technology and parametric modeling is carried out so as to rapidly acquire a specification list of timber processing, structural parameters of the members and edge and corner processing data of oblique arched mould pieces and guarantee straightness of a mouth-to-mouth ridge; and thus, waste of timber is avoided, cost is saved, and work efficiency is improved.