Distributed optical fiber vibration detection based on phase sensitive optical time domain reflectometer(OTDR) is an important protection method for early warning of submarine cable anchor damage. Aiming at the requirements of distinguish intrusion event types for detecting anchor damage of submarine cable, the backpropagation(BP) neural network classifier is applied to the submarine cable anchor damage prevention system based on Φ-OTDR. The principle of the submarine cable anchor damage prevention system based on Φ-OTDR+BP neural network classifier is introduced. The characteristics of signal in time domain and time frequency domain are used as feature vectors. A classifier based on BP neural network is constructed to recognize the types of intrusion events. The experimental results show that the pattern recognition accuracy of the classifier reaches 100%.