Foreign matter detection method and device

The embodiment of the invention provides a foreign matter detection method and device. The method comprises the steps of acquiring a pre-event image and a post-event image for a preset area; wherein the pre-event image is an image before a preset event occurs, and the post-event image is an image after the preset event occurs; identifying a target matched with the known target in the pre-event image as a pre-event target; identifying a target matched with the known target in the post-event image as a post-event target; respectively extracting feature information of each pre-event target and feature information of each post-event target; comparing the feature information of each pre-event target with the feature information of each post-event target, and detecting foreign matters in a target image; wherein the target image comprises the pre-event image and/or the post-event image. According to the embodiment of the invention, foreign matters appearing in the to-be-detected scene can bedetected. 本发明实施例提供了一种异物检测