The invention discloses a method for aligning, online detecting and correcting of a gearwheel. The method comprises the following steps that: A, alignment before
processing is performed, wherein an air supporting turntable is placed on a
workbench, and a bottom
slipway is inflated to ensure that the air supporting turntable is suspended on the surface of the
workbench, and proper alignment of the air supporting turntable and the work bench is adjusted; a workpiece is placed on an air supporting slide block, the air supporting slide block is simultaneously inflated to jack the workpiece, and a fine regulating device regulates the workpiece to be coaxial with the
workbench; an optical
theodolite is regulated to be coaxial with the air supporting turntable to complete the alignment; B, online detection is performed, an accurate
turn angle of workpiece is detected, and related gear precision and longitudinal
form error are detected; and C, based on online measurement, the gear precision is improved through alignment. The method can make the gearwheel easily moved, aligned, online detected and corrected on the workbench of a
machine tool through the air supporting slide block and the air supporting turntable, and obviously improve the
processing precision of the gearwheel.