Abstract: Collagen membrane was modified by gallic acid (GA), in which the effects of GA concentration, reaction time and pH were investigated on the mechanical property of collagen membrane. Firstly, single factor and orthogonal experiments were conducted in sequence by using the tensile strength and elongation at break of collagen membrane as the evaluation indexes, and the optimal GA modification conditions were obtained as the following: 5g/L of GA concentration, pH 6.0 and 4 h of reaction time. Then, using the unmodified collagen membrane as the control, the changes in structure and property of collagen membrane modified by GA were characterized by various tests including FI-IR, tensile strength, elongation at break, thermal stability, water resistance and antioxidant activity. Results indicated that the modification by GA could not lead to the damage of triple helix structure of collagen. Compared to the control, the tensile strength of GA-modified collagen membrane was increased by 16.1% and its thermal denaturation temperature was improved by 12.4%, while its water absorption was decreased by 15.1%. In addition, GA-modified collagen membrane exhibited the greatly improved scavenging capacities for both superoxide and hydroxyl radicals as well as antioxidant activity.