"Xi Yuan Ji Lu"(洗冤集錄) is the first systematic forensic writings in the world. But the original forensic researchers of the home and abroad only focus on the legal history and forensic History value of that. Speaking of the writing conditions of the book, most people give only a few words like "the Song Dynasty (宋朝) technological standards", or " the Song Dynasty(宋朝) Neo-Confucianism" rush with. So we try to use this article to give a full description about writing conditions of "Xi Yuan Ji Lu"(洗冤集錄), and try to provide the basis for further study of related issues.