This paper analyzes the scattered light intensity of three types of defects commonly encountered in glass wafer processing: particle defects, bubble defects, and triangular scratches. It is found that different defect structures have different scattered light in space. The strong distribution feature can establish the correspondence between the defect structure and the spatial distribution of scattered light intensity. At the same time, for the micron-scale defects on the wafer surface in the production line, the scattered light intensity of different size particle defects is calculated, and the micron-scale defect size is obtained. Therefore, a non-imaging defect detection method is proposed: detecting the scattered light intensity value and spatial distribution of the acquired defect, determining the defect structure by using the spatial distribution structure of the scattered light, and calculating the defect size by using the scattered light intensity, thereby indirectly determining the defect information, and achieving the purpose of defect detection.It can provide a methodological reference for rapid detection of defects in the wafer industry application process.