Allama Muhammad Baqir Majlisi has collected a huge volume of historical reports in his Bihar al-Anwar Encyclopedia. Given that his main goal as a "hadith" was to compile an encyclopedia of hadith to prove the legitimacy of the Ahl al-Bayt (a.s.), the fundamental question arises as to what methods he used in practice to criticize and analyze these reports. The main challenge is to go beyond the one-dimensional idea of ​​the dominance of theological perspective and to accurately identify the tools of his historical criticism. This article uses a descriptive-analytical method and based on the theoretical framework of "internal and external criticism", to systematically categorize and analyze Allama Majlisi's methods of criticism. The research findings show that Majlisi used a variety of methods. In the field of external criticism, he uses a source-based approach to identify adaptations and compare texts. In the field of internal criticism, on the one hand, he uses rational and lexical tools to refute the news that contradicts the Quran and corrects textual errors, and on the other hand, he resolves conflicts by using historical-temporal evidence. However, these tools are influenced by his theological assumptions when faced with the principles of belief. Majlisi relies on “rational possibility” and the reliability of the source to defend miracles and extraordinary affairs, and to preserve the principle of “infallibility” and resolve apparent conflicts in the words and behavior of the Imams (a.s.), he uses the concept of “taqiyyah” as an efficient interpretive tool. Finally, this study