The invention provides a method and a device for improving an effect of a camera shooting in dark. The method comprises the following steps of: setting a maximum limit value of light sensitivity of a sensor of the camera; setting a lower limit threshold value of image brightness of a picture; judging whether the brightness of a viewed image is less than the lower limit threshold value of the image brightness; if not, entering into a normal photo mode; and if yes, entering into a darkness photo mode. According to the technical scheme provided by the embodiment of the invention, the ambient brightness is judged through the brightness of the viewed image, and if the ambient brightness is judged to be at a low light state, the light sensitivity of the sensor is adjusted to be the maximum limit value, an exposure time is adjusted, and the brightness of the photo can meet the required brightness, so that the effect of shooting in dark is improved, and the photo with higher brightness is obtained under the condition without changing the sensor of the camera.