Mobile differential optical absorption spectroscopy (DOAS) is used to study regional distribution of SO₂ and NO₂ column density in the North China Plain and its impact on the Beijing region under different wind fields during June and July in 2013. High SO₂ and NO₂ concentration values around Shijiazhuang, Baoding and Jinan areas are observed simultaneously, indicating that there are industrial emission sources in these areas. Average values of SO₂ and NO₂ around the Shijiazhuang area on June 11th are 1.29×10¹⁷ molecule·cm^-2 and 3.59× 10¹⁶ molecule · cm^{- 2}, respectively, which are 3.8 times and 3.6 times of the average in low concentration area respectively. Shijiazhuang- Baoding- Beijing direction can be a transportation pathway in steady south- west wind field, and the conclusion is verified by the Hysplit model. NO₂ column density obtained by mobile DOAS is compared with that by ozone monitoring instrument(OMI), and the good agreement is found. The satellite observation also proves existence of the transportation pathway in south wind field. The experimental results show that mobile DOAS plays an important role in detecting emission sources, rapidly obtaining regional distribution of air pollutants and validating satellite data.