The disclosure provides a data packet classification method and system based on a convolutional neural network including merging each rule set in a training rule set to form a plurality of merging schemes, and determining an optimal merging scheme for each rule set in the training rule set on the basis of performance evaluation; converting a prefix combination distribution of each rule set in the training rule set and a target rule set into an image, and training a convolutional neural network model by taking the image and the corresponding optimal merging scheme as features; and classifying the target rule set on the basis of image similarity, and constructing a corresponding hash table for data packet classification.