The invention relates to a fabricated vierendeel steel truss integrated floor module and an assembling method thereof. The fabricated vierendeel steel truss integrated floor module comprises a vierendeel steel truss, floor structure modules composed of concrete floor layers, and a steel structure girder. The upper surface of a vierendeel steel truss unit is provided with a plurality of shear pegs. The concrete floor layers are supported on the vierendeel steel truss unit, and the shear pegs are inserted into the concrete floor layers. Bracket are arranged at joints of the vierendeel steel truss and the steel structure girder. The floor structure modules are connected through end plates where bolt holes are reserved. According to the fabricated vierendeel steel truss integrated floor module and the assembling method thereof, a main structure member and floors are prefabricated and spliced in a plant, meanwhile, an integrated part or all equipment pipelines and suspended ceilings form a unit type floor system, module production is achieved, an operator just needs to connect the system through bolts and then conduct seam treatment at the site, operation is simple, a conventional steel structure mounting method in which welding is conducted at the site is avoided, the project quality is ensured while the construction period is effectively shortened, and industrialization, assembly and standardization of the construction industry can be impelled advantageously.