This article examines the rule of urgency and its effect on secondary rulings, civil and criminal law through documents such as the Qur'an, Sunnah, common sense, consensus, and secondary rulings. The article analyzes the concept of emergency rule from the point of view of legal documents and examines the influence of Quran and Sunnah in the formation and process of this rule. Also, it analyzes the secondary rulings by observing the conditions and descriptions, and in exceptional circumstances, it offers the possibility of ignoring the primary ruling and canceling it. A look at the interpretation of secondary rulings by jurists such as Imam Khomeini has also been taken, and the relationship between secondary and primary rulings has been discussed and investigated separately by analyzing the reasons for each ruling. By using library, internet and descriptive and analytical methods, the article compares the documentation of emergency rule and its relationship with secondary rulings and presents improved results in better understanding of this rule and its applications in the field of civil and criminal law.