Spectra interpolation is used to analyze differential optical absorption spectroscopy (DOAS) spectra, which can greatly decrease the absorption elimination error of the high concentration species and achieve accurate measurements of trace compounds including NO3, glyoxal ((CHO)2 ), mono-aromatic hydrocarbons (MAHC), et al by DOAS. The changes of high pressure Xe arc lamp (called Xe lamp for short) structure, resulting from the changes of temperature and pressure, are simulated accurately, which enables the analysis of indicator of atmospheric photochemical reaction -(CHO)2 without the interference of Xe lamp structure (more than one hundred times higher compared with (CHO)2) near 450 nm. The mass dependent absorption structure of H2O is simulated and the accurate measurement of the “cleaner” of nocturnal atmospheric pollutant -NO3 is achieved without the interference of nonlinear absorption of H2O near 662 nm and 623 nm. The mass dependent absorption of O2 and the temperature dependent absorption of O3 are simulated, which enables the accurate measurement of MAHC in the range of 250～285 nm free of the effect of much higher absorption of O2 and O3.