Optical coherence tomography (OCT) is a technique that uses the principle of scattered light coherence for imaging, with features of no destruction, fastness high resolution, and cross-sectional imaging. The identification of physical evidence requires as far as possible to extract, inspect, analyze and obtain valuable information without destroying its original state. As an optical inspection technology, OCT can meet these requirements. It can realize real-time, in-situ and non-destructive imaging without pre-processing the sample, which is of great significance in physical evidence identification. We introduce the working principle of OCT and its application in the field of physical evidence identification.