A method for retrieving aerosol extinction coefficient vertical profile based on multi-axis differential absorption spectroscopy was studied, which is based on nonlinear optimal estimation algorithm. The aerosol extinction profile and optical thickness are retrieved from the concentration of O4 gas differential diagonal column, combined with the atmospheric radiation transmission model, by the multi axis differential absorption spectrometer. Field observation experiments were carried out in Huaibei area in July and August, 2017. The difference between the simulated results of O4 differential column with low elevation angle (less than 15 degrees) is higher than 0.9, and the aerosol state of troposphere is well retrieved. The study shows that the overall aerosol content in Huaibei is low in summer, and the daily average optical thickness of the two day high value weather (July 24th and August 12th) is 0.65 and 0.59, respectively, 1.6 times and 1.4 times the seasonal average. Through the aerosol extinction profile time series, we can see that the high values of aerosol over two days are below 0.5 km, and the pollution is mainly caused by local accumulation.