The invention provides a monitoring area change detection method and device and a storage medium, and the method comprises the steps: obtaining an initial state image and a monitoring image of a monitoring area, and enabling the monitoring image to be an image, collected after the initial state image collection time, of the monitoring area; determining the change intensity of each pixel of the monitoring area according to the initial state image and the monitoring image, and generating a change intensity graph of the monitoring area according to the change intensity of each pixel; carrying outbinarization output on the change intensity graph; determining a plurality of output areas according to the binarized output change intensity graph, and calculating the number of pixels occupied by each output area; judging whether the number of pixels occupied by each output area exceeds a preset threshold value or not; and if not, deleting the output area of which the pixel number does not exceed the preset threshold, and calculating the change degree of the monitoring area according to the total pixel number of the remaining output area and the total pixel number of the change intensity graph.