The clinical application of fast track surgery (FTS) is widely accepted, which reduces stress and postoperative complications incidence, enhances patient's immune function through the clinical application of multidisciplinary intervention, and thereby achieves a rapid postoperative recovery and shorter hospital stay. Natural killer (NK) cell, considered as the body's first-line resistance to viral infection and tumor, plays an important biological role against virus, tumor, and in immunomodulatory mechanism, et al. With the review of activation mechanism of NK cells, a certain relationship between the stress response and the activation of NK cells is found. Through reducing the body's stress response, FTS can produce a series of cytokines and metabolic hormone changes in the internal environment, thus indirectly or directly activating NK cells.