Immune checkpoint inhibitors (ICIs) have revolutionized the treatment landscape for malignant tumors such as advanced lung cancer, but their efficacy is limited. In recent years, the circadian rhythm has provided a brand-new optimization strategy for immunotherapy. This perspective article aims to explore the potential mechanisms of the interaction between immunotherapy and circadian rhythms, reviews clinical evidence supporting that "time-of-day receipt of ICIs brings better therapeutic effects", and conduct an in-depth analysis of the current practical challenges of chrono-immunotherapy. And emphasize the potential of "chrono-immunotherapy" as a valuable therapeutic approach.