Abstract: Atmospheric dielectric barrier discharge (DBD) plasma has a broad application prospect in wastewater treatment. O₃ and N₂O are important components of atmospheric plasma, and are affected by many factors. Highprecision realtime measurement of O₃ and N₂O concentrations in plasma is of great significance for optimizing discharge parameters and reactor design. Mass spectrometry has high specificity and sensitivity, and can simultaneously obtain the component concentrations of various substances and their changes with time. This research solved the traditional mass spectrometry is applied to hard under the condition of atmospheric pressure dielectric barrier discharge plasma active products measure and the problem of mass spectrometer is susceptible to interference of strong electric field, and designed a set of atmospheric pressure using quadrupole mass spectrometer O₃ and N₂O in the DBD plasma components of measurement system. At atmospheric pressure of 101.325 kPa, plasma was generated on a six-tube coaxial dielectric barrier discharge structure by a high voltage power supply with microsecond pulse width. The experimental results showed that the control voltage and the air flow have great influence on plasma component concentration. When the control voltage is 200 V, the composition of O₃ and N₂O is higher than that of other control voltages. When the control voltage is 200 V and the air flow is 7.8 L/min, the concentration of O₃ reaches the highest. The concentration of N₂O reaches the highest when the air flow rate is 3.8 L/min. The measurement methods and experimental results have important application value in the optimization of DBD reactor, the control of key parameters, and the application of dielectric barrier discharge plasma at atmospheric pressure.