The offensive operation of Beit Al-Maqdis, which led to the liberation of the heroic Khorramshahr and about 6000 square kilometers of the territory of our beloved country from the clutches of the Baathist regime in Iraq, was carried out without the operation of crossing the roaring Karun river by the Fatah and Nasr camps and the passage of their troops and equipment through five floating bridges. It was impossible by the engineering units of the Army of the Islamic Republic of Iran, especially since these bridges had the feature of two-way traffic and had no restrictions in this regard. By looking at the events and the role of engineering in Jerusalem operations in the areas of crossing the river and crossing artificial barriers, the authors have tried to express the engineering activities in this important and fateful operation; The main research question is about the role of engineering in Jerusalem operations. The engineering staff, including the engineer commanders and veteran professors of the engineering faculty, who participated in the Jerusalem operation, and all the documents and materials collected from experts, are the community studied in this article. The research method is descriptive with quantitative-qualitative (mixed) data analysis approach. Information data has been collected by field and library methods and with interview and questionnaire tools and analyzed using descriptive statistics. The findings of the article confirm that the ground force's combat engineering had an important and decisive role in the victory of the Jerusalem operation