The conflict between reason and Sharia is one of the important philosophical issues that Mulla Sadra specifically addressed. His view on the cognitive error of reason has had a direct impact on resolving the conflict between reason and Sharia. Therefore, the main question in this research is how Mulla Sadra dealt with the problem of the conflict between reason and Sharia based on his view on how error occurs. Mulla Sadra considers reason and Sharia to be immune from error, and considers the error of reason to be due to internal and external factors, and the error in understanding Sharia to be due to defects in the chain of transmission or implication. He believes that there is complete harmony between these two sources of knowledge, and considers a true conflict between reason and Sharia to be impossible. he considers the belief of those who believe in the necessity of rigid adherence to imitation and following appearances to be due to their weakness of intellect and lack of insight, and she also considers the view of those philosophers who have gone too far with intellect and have used it to negate the definitive matters of the Sharia to be due to the corruption of their conscience, and she considers both to be on the path of excess and excess.