A ground-based Multi-Axis Differential Optical Absorption Spectroscopy （MAX-DOAS） with the characteristics of simple operation， wide range and high sensitivity was constructed， and the time series of HCHO in Huaibei area from October 2019 to May 2020 were obtained continuously. In order to reduce the interference of other gases， different bands are used to retrieve the differential slant column density of HCHO. Through comparison， it was found that when the band of 324~342 nm was selected， the inversion error fluctuation is the minimum， and the concentration of HCHO gas can be obtained precisely. According to the results of HCHO monthly mean values， compared with the before and after COVIN-9 epidemic ，the concentration of HCHO in the COVIN-9 epidemic were decreased by 35% and 23% respectively. The results of daily and weekly variations respectively showed that HCHO concentration in Huaibei area have daily variation characteristics of high in the morning and evening and low in noon， and there is no obvious weekend effect. Combined with Hysplit wind field backward trajectory model， the wind field of high value weather was studied. It was found that during January 12~14 and 18~21， 2020， under the influence of northwest wind field， the pollution transport from Dangshan and other places in Huaibei area will be affected， which will lead to the increase of HCHO concentration. The result of MAX-DOAS measurement of HCHO vertical column density were compared with the OMI satellite data， and it was found that the two methods had good consistency （R² = 0.87）.