Islamic Economics can be taken as an integrated science which is so considered in recent years based on codified methods for integration of bi-disciplinary. These methods that are used in accordance with integration of bi-disciplinary approach in global academic sessions, can be categorized as: Parallel Disciplinary Approach, Multi-Disciplinary Approach, and Supra/Trans-Disciplinary Approach. Nevertheless integrated approaches already drew attention of so many experts as the most designated basis of Islamic economics design model. But, there is a significant issue that is natural difference of Islam and economics as two integrated disciplines. So that economics is a human science while Islam is a divine religion. Therefore mentioned methods have not any compatibility in Islamic economics science and needs deep understanding of islamic concepts (power of Ijtihad) as the complementary element.
From the point view of the method, this research based on approaches of bi-disciplinary integration, while tries to propose its analysis about necessity of deep understanding of Islam, proves that in spite of difference in difficulty level of applying those approaches, deep understanding of Islam in any approach is vital, and direct joining of these two disciplines is not possible unless to be done by an expert one and this expertise cannot be accomplished unless with Ijtihad, comprehending in religion and this issue can be applicable and possible with due to different level of exegesis in shia fighh.