The vertical column density (VCD) of tropospheric SO2 was obtained by using multi-axis differential optical absorption spectroscopy (MAX-DOAS). And differential slant column density (dSCD) of SO2 was got by using different reference spectra and different wave bands. By comparison, the error and the variation of error was minimum when using the sequential reference, and the error was less than 5%. Six wave bands were selected and compared to determine the optimal retrieval wave band which was 307.5～315 nm. Combined with meteorological data, a contamination process from 14th to 18th, October, 2015 was studied. The data analysis showed that wind speed and direction were two important factors affecting the concentration of SO2 in monitoring site. The SO2 produced from city and power plants was transported to monitoring site under the influence of east and south wind. According to the research, MAX-DOAS can accurately inverse the atmospheric SO2 VCD, which has great significance for exploring the tropospheric SO2 VCD of the city, satellite calibration, model validation and studying pollution transport.