The invention is applicable to the technical field of image recognition, and provides an image-based anti-incorrect-entry interval method and device and a terminal device, and the method comprises thesteps of obtaining an interval identification image sent by a head-mounted device, and carrying out recognition on the interval identification image, and obtaining the current identification information; comparing the identification information with the pre-stored identification information in a current task, and if the identification information is consistent with the pre-stored identification information in the current task, generating and sending the operation prompt information to the head-mounted device according to an operation instruction in the current task; and obtaining a key step operation image sent by the head-mounted device, identifying the key operation information, comparing the key operation information with the current operation instruction, and determining whether the operation of the worker is standard or not. According to the method, whether a worker enters a wrong interval or not can be prompted by identifying the interval identifier, meanwhile, the key steps during the maintenance process are subjected to image identification, so that the phenomena of false detection and missed detection during the maintenance process are avoided, and the operation of the worker is standardized.