In order to obtain the visibility more conveniently and quickly and realize the long-term observation of the visibility, the visibility extraction method of the video image based on the theory of the dark channel prior is analyzed and studied. Through the brightness analysis on the target images observed at different times of the day, the corresponding atmospheric transmittance and visibility can be obtained. Furthermore, the visibility extraction results are compared with the measured lidar visibility data under the same conditions. The results show that the extracted visibility results are in good agreement with the measured data, and the correlation coefficient reaches 0.96616.