The total atmospheric transmittance is an important parameter reflecting the optical properties of the atmosphere. In the fields of atmospheric radiation, remote sensing, air quality monitoring and opto-electronic engineering, it is necessary to make a deep study on the atmospheric transmittance. In this paper, the methods of acquiring atmospheric transmittance were discussed in detail, and the latest progress and related problems of different acquisition methods were analyzed. The characteristics of software based simulation and direct measurement were compared and analyzed, and at the last, the future research was also prospected.