Embodiments of this application disclose a target tracking method and apparatus, a device, and a medium. The method includes: obtaining, by a server, a first video stream, and performing the following data processing for each video frame in the first video stream: performing, by the server, detection according to a target detection model and a current video frame, to obtain candidate regions in the current video frame; performing, by the server, extraction according to a feature extraction model and the candidate regions, to obtain a deep feature corresponding to each candidate region; calculating, by the server, a feature similarity corresponding to the each candidate region according to the deep feature corresponding to the each candidate region and a deep feature of a target detected in a previous video frame; and finally determining, by the server based on the feature similarity corresponding to the each candidate region, the target detected in the current video frame. Target detection is performed in a range of the current video frame by using the target detection model, and target tracking is performed based on the deep feature, so that occurrence of cases such as a tracking drift or losing a tracking target can be effectively prevented, to ensure the accuracy of target tracking.