An image analysis method is provided. In the image analysis method, a to-be analyzed image is inputted into a region-based convolutional neural network (RCNN) model to obtain a masked image outputted from the RCNN. The center of a masked object in the masked image is calculated. The center is regarded as an origin of coordinate and the farthest coordinate point from the origin of coordinate in each of the four quadrants relative to the origin of coordinate are searched. The image analysis block is generated for each of the farthest coordinate points. The post-processing is performed on the image analysis blocks to obtain an object range.