Subsurface microcracking is an unavoidable consequence of the quartz glass grinding process， and it significantly affects the service performance of optical components. Therefore， nondestructive detection of subsurface microcracks in quartz glass is crucial for grinding process optimization. Accordingly， herein， a polarized laser scattering （PLS）-based method for detecting subsurface microcracks in quartz glass was developed. For this， a PLS nondestructive inspection platform was established. Indentation specimens with subsurface microcrack depths of 5.27， 9.7， and 15.42 μm were prepared via indentation experiments at pressure values of 20， 50， and 100 mN， respectively. Furthermore， ground specimens with subsurface microcrack depths ranging from 1-10 μm were prepared via grinding with different abrasive particle sizes （1-20 μm）. A power function relationship between the PLS detection signal and subsurface crack depth was discovered. The developed PLS detection system effectively detected and quantified subsurface microcracks with depths less than 10 μm. Thus， the developed PLS detection system enables microcrack detection in ground quartz glass， providing valuable guidance for subsurface microcrack control and process optimization.