An automatic exposure control method is used to control a shooting exposure parameter for shooting an image by a shooting end. At least one middle brightness value is acquired between a brightness value of a background region and an overall brightness value, and then a relation between working distances of a flash light and a practical distance of an object is determined sequentially from the brightness value of the background region to extend towards the overall brightness value, in which the working distances of the flash light are respectively corresponding to the brightness value of the background region, the middle brightness values, and the overall brightness value, so as to obtain a shooting exposure parameter and to selectively activate the flash light, thereby adjusting the overall brightness of the image to be shot, so as to obtain an image with a proper overall brightness.