Visibility is one of the most important gists in military area. For example, airplane and ships’ safely navigating need this parameter, demarcating radar or photoelectric equipment needs it and all the military strike needs it too. In this paper, the definiens of the visibility was first expatiated, and then the measurements of the visibility detecting and the theory of it were illuminated, including imaging method, aerosol sampling method, optical parameter calculating method and so on. Except that, the character and the applying area were discussed. In the end, a conclusion was pointed that visibility detecting with backscatter signal would become emphases in the future study.