The invention discloses a small adversarial patch generation method and device, and the method comprises the steps: carrying out the random initialization of an adversarial patch image, adding the initialized adversarial patch image to a selected pasting region on a target object in training data, and manufacturing an adversarial sample; transmitting the adversarial samples into a deep learning model for adversarial feature extraction, and transmitting benign samples without adversarial patch images into the deep learning model for benign feature extraction; jointly inputting the adversarial features and the benign features into a feature enhancement loss function for loss calculation to obtain a loss result; adding a loss result into a model loss function, and updating a pixel value of the adversarial patch through an optimizer after back propagation; and after preset times of iteration, enabling the adversarial patch to enable the deep learning model to output an error result, and ending the adversarial patch processing process. According to the method, the size of the anti-patch in the physical world can be smaller, the manufacturing cost is reduced, the identifiability of the anti-patch is reduced, and a defense method based on detection is broken through more easily.