Automatic exposure control method

The invention provides an automatic exposure control method. The method comprises the following steps of: a) obtaining a pixel value of an image; b) adjusting an integral time and gain of the image based on the pixel value feature of the image; c) judging whether or not the integral time and the gain are adjusted to predetermined target values at present; if not, entering the next step; d) judging whether the integral time and the gain are both adjusted to maximum values or minimum values at present; when the integral time and the gain are both adjusted to the maximum values but not to the target values, obtaining a pixel value with high flexibility, and performing the step b; and when the integral time and the gain are both adjusted to the minimum values but not to the target values, obtaining a pixel value with low flexibility, and performing the step b. by the embodiment of the invention, the confliction that the brightness of an image does not reach the requirement when the integral time and the gain reac