The invention discloses a method for manufacturing heat insulation bridge-cut-off aluminum alloy window, which comprises the following steps of: 1, cutting section bars: cutting a heat insulation bridge-cut-off main section bar by adopting a stepless speed regulation type section aluminum two-angle cutting saw and obtaining a plurality of frame section bars used for assemblying a window frame; 2,processing drain holes, hardware installing holes and section bar end faces by adopting a profiling machine or multifunctional milling and drilling machine; 3, installing a sealing strip: mounting a three-stage sealing strip consisting of a K-shaped adhesive tape and two sealing wool tops on the cutting end face of the frame section bar, from the step 1 to the step 3, synchronously completing glazing bead and angle code cutting; 4, punching a group angle, synchronously completing the manufacture of a glass window in steps from the step 1 to the step 4; 5, combining and installing the frame; 6, assembling depression bars; and 7, assembling hardware fittings. The invention has the advantages of reasonable design, convenient and simple construction operation, high construction efficiency, high cutting precision and convenient realization; and the processed heat insulation bridge-cut-off aluminum alloy window has the advantages of high quality, good insulation property, excellent noise and sound prevention performance and long service life.