Undoubtedly, cultural security as a platform for preserving and improving the culture and cultural progress of any society is one of the basic necessities in this direction, which should be based on correct and accurate rationality. Therefore, this article paid attention to the cultural security of the Prophet's (PBUH) era and adapted and analyzed it to the rational standards of the thought of the leaders of the Islamic Revolution of Iran in line with modeling and analyzing the role of rationality in cultural security to explain and analyze the rational balance of cultural security for the Islamic revolution and the new Islamic civilization on the ideological criteria and intellectual and rational school of Islam. Thus, the question of this research is what was the role of rationality in the cultural security of the Prophet's period and what is its role in the cultural security of the Islamic Revolution of Iran based on the thought of the Leaders of the revolution? The article has analyzed the role of rationality in providing cultural security by using thematic analysis method in this direction studied responding, defending and explaining logically and rationally to the attacker's propositions, logically and rationally directing behaviors and actions, rationally functioning cultural tools and media in defense of Islamic culture and the rational role of Islamic unity, convergence and public participation.