Subsurface damage of optical components directly affects the laser damage threshold of optical systems, and the damage depth is one of the key parameters for measuring subsurface damage, for which there is no mature and rapid quantitative measurement method. A damage depth measurement method based on fluorescence microscopy stereoscopic imaging is proposed. First, during the processing of optical components, quantum dots are used to mark the subsurface damage; when the laser beam is incident on the surface of the optical component at a certain angle, the marked quantum dots are excited to generate fluorescence; the fluorescence signal of the longitudinal distribution of the damage layer is imaged microscopically by a fluorescence camera, and the fluorescence distribution depth is calculated according to the imaging principle and structural parameters to achieve rapid quantitative measurement of the sub-surface damage depth of the optical component. A series of standard parts are prepared by optical glue and glue dumping process, and comparative verification measurement experiments are carried out, and the results show that the proposed method can measure the damage depth of 55~75 μm with a relative error of less than 8%.