The invention provides a bird nest detection method and system based on deep learning, and relates to the technical field of image detection, and the method comprises the steps: obtaining an on-site image of power transmission equipment, carrying out the transformation processing of the on-site image, and obtaining a transformation image, so as to jointly construct a sample database; Establishinga detection model of deep learning; Inputting the images in the sample database into a detection model for iterative training until preset training accuracy is achieved; Obtaining an image with a birdnest on the power transmission equipment to construct a verification set, and inputting the image in the verification set into the detection model for verification until preset verification accuracyis achieved; Obtaining an image with a bird nest on the power transmission equipment to construct a test set, and inputting the image in the test set into the detection model for testing until presettest accuracy is achieved; And inputting the to-be-detected image into the detection model for detection so as to output a target defect image. According to the bird nest detection method provided bythe embodiment of the invention, the bird nest condition on the power transmission equipment can be intelligently checked, and the real-time performance of obtaining the bird nest condition information is improved.