The invention relates to an aluminum-alloy-profile drilling device based on polar coordinates and belongs to the field of industrial production equipment. The aluminum-alloy-profile drilling device ischaracterized in that a drilling device body is mounted at the top end of a first motor, a first hydraulic cylinder is fixed on a first support, a bottom plate is fixed on a second support, a slide retaining plate is mounted on a third support, a second hydraulic cylinder is mounted at the center of the bottom of the bottom plate, a control device is mounted on the left of the rear of a workbench, an ultrasonic sensor is fixed at one end of a length regulating plate, the first motor is fixed on a first motor base and at the center of the rear of the workbench, and a fixing device is mounted at the center of a fixed retaining plate. The aluminum-alloy-profile drilling device has the advantages that a drill bit can be moved to a position which needs to be drilled by the rotation of the first motor and a second motor so as to satisfy the different requirements of aluminum alloy profiles of different shapes, manpower use is reduced, efficiency and precision are increased, and worker safety is guaranteed.