For NO_x pollutions in Wuhan during the outbreak of COVID-19, we applied a mobile MAX-DOAS and a portable ultraviolet DOAS to cooperatively measure NO_x concentration in the third ring road of Wuhan from Feb. 29 ^th to Mar. 14 ^th, 2020. The mobile MAX-DOAS acquired the vertical column concentration (VCD) distribution of NO₂ along its course and the portable ultraviolet DOAS measured the NO and NO₂ concentrations to calculate [NO_x]/[NO₂]. Then, the NO_x emission flux and its error of the third ring road of Wuhan were calculated in conjunction with the data of the wind field. The results show that the NO_x emission flux during the measurements in the third ring of Wuhan ranges from 7.78 mol/s to 15.71 mol/s, about 10.78 mol/s on average. Compared with the average [NO_x]/[NO₂], the real-time [NO_x]/[NO₂] along the route of the mobile MAX-DOAS derived from the portable ultraviolet DOAS could effectively reduce the error of NO_x emission flux caused by the [NO_x]/[NO₂] error. However, this method is not recommended in scenarios with substantial near-surface NO_x emission sources.