Image traces refer to the reflection bodies with external structural characteristics produced by tangible objects on another object. The theory of identity recognition is the scientific foundation of image trace inspection, which has been summarized and widely applied in the field of trace inspection through long-term judicial practice. The inspection of image traces has gradually improved with the development of science and technology, but the scientific validity of identifying certain image traces remains questionable. This article explores the scientific issues in the identification of various types of image traces by sorting out the theories and models of the identification of image traces. It is believed that the identification of image traces can be improved in three aspects: 1. Strengthen the research on digital and automated comparison methods, and establish databases of various types of trace features; 2. Standardization and normalization of the trace inspection process; 3. Refine the likelihood ratio evaluation method for image traces.