Environmental trace gases monitoring instrument (EMI) was launched on May 9th, 2018, which can effectively acquire global ultraviolet-visible signal of atmosphere scattering. EMI raw digital number(DN) is called level 0 data. For quantitative application of EMI sensing data, spectral calibration, geometric positioning and radiometric calibration are required. Then the level 1 data is obtained. The level 1 data is used as input for scientific atmospheric retrieval algorithms. Retrieval results are applied to quantitatively monitor the global air quality changes and the transmission of pollutant gases distribution, which could get spatial and temporal distribution and variation of key global atmospheric composition and pollutants (such as NO2, SO2, O3, etc.).