Bozhong 34-9 Oilfield located in Bozhong 34 Embanked Zone is the first large-scale oil field in the offshore igneous rock developed region of China. The target reserviors of Bozhong 34-9 Oilfield are Dongsan Part and Shahejie Formation. In order to strengthen reservoir protection and increase oil and gas production， this paper analyzes the reservoir lithology， porosity and permeability characteristics and fluid characteristics， and evaluates the cores from the reservoir in terms of velocity sensitivity， water sensitivity， salt sensitivity， alkali sensitivity and acid sensitivity. It is intended to evaluate reservoir damage factors intuitively and quantitatively， and put forward proper suggestions to prevent and reduce reservoir damage， which is of great practical significance to reservoir protection for the Bozhong block.