The invention provides an image quality detection method for a photoetching machine. The method comprises the steps of providing a wafer, forming a plurality of mutually spaced hole patterns in the surface of the wafer, scanning the defect of the hole pattern to obtain a defect image; and analyzing the defect image to judge whether the defect image is abnormal, so as to monitore whether an imagingplane of a camera lens of the photoetching machine is abnormal at regular intervals. The method increases the monitoring frequency, no down machine is needed, the time consumed on monitoring is shortened, the detection method is higher in sensitivity, the problem is discovered timely when the imaging plane of the photoetching machine becomes abnormal on the initial stage, and the loss of the product yield is avoided.