The invention relates to a break-angle type two-stage diaphragm wall cold joint waterproof method and structure. The break-angle type two-stage diaphragm wall cold joint waterproof method comprises the steps that drilled piles tangent to two-stage diaphragm walls are constructed through full casing full whirling driller at the corner of the two-stage diaphragm walls; a high pressure gas nozzle isused for removing soil bodies and mudcake between the drilled piles and the two-stage diaphragm walls, and between the drilled piles; and self-setting materials are reinjected to the drilling piles toform a water-stop reinforcing body. The drilling piles has high rigidity and a small perpendicularity deviation, cold joint leakage of water or even water gushing caused by pre-embedded joint failureor poor perpendicularity of the diaphragm walls can be effectively prevented, the waterproof quality of cold joints is improved, and engineering risks are reduced.