Objective To investigate the dynamics of NK cells and Treg cells， as well as their potential prognostic significance in relation to TKI discontinuation among patients diagnosed with chronic myeloid leukemia （CML）. Methods In this study， a total of 200 patients diagnosed with CML were randomly selected and divided into two groups： the discontinuation group （n = 100） and the non-discontinuation group （n = 100）. Within the discontinuation group， patients were further categorized into a recurrence subgroup （n = 41） and a non-recurrence subgroup （n = 59）. Clinical data and follow-up information of these patients were retrospectively analyzed. Logistic regression analysis was performed to investigate the impact of various variables on patient outcomes following drug discontinuation， as well as to explore independent factors influencing recurrence in these individuals. Receiver operating characteristic （ROC） curve analysis was employed to assess the predictive value of NK cells and Treg cells for TKI discontinuation outcomes. A significance level of P < 0.05 was considered statistically significant. Results The proportion of patients treated with interferon in the discontinuation group was significantly higher than that in the non-discontinuation group （P < 0.05）. Moreover， the former group exhibited a significantly higher number of NK cells （P < 0.05） and Treg cells （P < 0.01） compared to the latter group. Compared to the recurrence group， there was a significant increase in the proportion of patients using interferon in the non-recurrence group （P < 0.05）， along with longer durations of TKI treatment and deep molecular response （DMR） duration （P < 0.05）. The number of NK cells and Treg cells in the non-recurrence group was significantly higher than that in the recurrence group （P < 0.01）. Logistic regression analysis found that the use of interferon （OR = 1.25， 95% CI： 1.11 ~ 2.03， P < 0.001）， duration of DMR （OR = 1.16， 95% CI： 1.08 ~ 1.92， P < 0.05）， NK cells （OR = 1.64， 95% CI： 1.14 ~ 2.28， P < 0.01）， and Treg cells （OR = 1.83， 95% CI： 1.15 ~ 2.42， P < 0.01） were all influencing factors for the recurrence of patients after drug discontinuation. The results of ROC curve analysis showed that the AUC of NK cells combined with Treg cells for predicting the recurrence of TKI after discontinuation was 0.892 （95% CI： 0.857 ~ 0.927， P < 0.001）. Conclusion The frequencies of NK cells and Treg cells were significantly elevated in patients who remained recurrence-free following TKI discontinuation， highlighting the potential predictive value of combined NK cell and Treg cell analysis for drug cessation in CML patients.