Abstract: The effect of different blanching temperature, blanching time, solid- to- liquid ratio and citric acid addition on the PPO ( polyphenoloxidase) activity and browning degree of banana peel serous were studied through a L9 ( 34) orthogonal test.The results indicated that the optimal condition to carry out a banana peel heat treatment required a heating duration of 5min, 100℃'s heating temperature, a 1 ∶ 6 solid- liquid ratio and 0.6% 's citric acid addition.Under such conditions, the polyphenoloxidase activity was 16 U and the browning degree of banana serous was only 0.117, the color protection of banana peel and its freshness were efficiently enhanced in banana peel processing.