Atmospheric pressure cold plasma has shown multiple biological effects of anti-bacteria and anti-cancer. In this study, the effect of atmospheric pressure cold plasma on respiratory inflammation and oxidant stress is explored. Tunicamycin was used to stimulate human bronchial epithelial cells (HBECs) and A549 cells for inflammatory response and oxidative stress, followed by atmospheric pressure cold plasma treatment. For HBECs and A549 cells, atmospheric pressure cold plasma was able to alleviate tunicamycin-induced cell proliferation inhibition, inflammation and oxidant stress, and enhance nuclear factor-erythroid-2-related factor 2 (NRF2) pathway activation. Moreover, NRF2/ARE (anti-oxidant response elements) pathway was involved in the regulation of atmospheric pressure cold plasma on tunicamycin-induced oxidative stress. These results suggest the positive effect of atmospheric pressure cold plasma on inflammation and oxidant stress of respiratory system, indicating the therapeutic potential of atmospheric pressure cold plasma for respiratory diseases.