The invention discloses a cutting device for foam boards for building wall face insulation. The cutting device comprises a bottom plate, a first motor, a second motor, a transmission shaft, a moving plate, a pressing plate, an air cylinder and a fixing block; the cutting device is characterized in that the bottom plate is arranged on brackets; a connecting plate is arranged between the brackets; the first motor and the second motor are arranged on the connecting plate; connecting shafts are arranged at the two ends of the transmission shaft; the transmission shaft is arranged at the two ends of the bottom plate through the connecting shafts; and the moving plate is provided with a positioning block and a fixing frame. The pressing plate is of a structure of which the height can be adjustedon the fixing frame through an adjusting screw and a clamp nut, the stability of the foam boards needing to be cut on the moving plate is improved through the pressing plate, the stability of the foam boards in the cutting process is improved, the cutting quality of the foam boards is improved, the position of the pressing plate is adjusted according to the foam boards of different thicknesses, the application range of the cutting device is enlarged, and the cost for manufacturing a plurality of sets of cutting devices is reduced.