Insulin is an important protein hormone that participates in multiple metabolic pathways. Biosynthetic insulin has been widely used in the treatment of type 1 and type 2 diabetes. Currently, the number of reported cases of insulin overdose both at home and abroad is gradually increasing, and insulin homicide is no longer a means of “committing murder without leaving a trace”. At present, there are no systematic protocols for the identification of insulin overdose in the field of forensic medicine in China. This article introduces the causes, toxicological characteristics, forensic examination, laboratory testing methods and indicator reference of insulin overdose. Based on the identification practice and research results and referring to relevant studies on insulin overdose at home and abroad, this paper aims to provide recommendations and references for the formulation of forensic identification guidelines for insulin overdose cases.