Background: The crosstalk between trophoblast cells and decidual NK cells plays an important role in the establishment and maintenance of normal pregnancy. Recent studies have reported autophagy can induce immune tolerance at the maternal fetal interface, but the mechanism is largely unclear. Methods: Autophagy levels in the villi of normal and recurrent spontaneous abortion (RSA) patients were detected by transmission electron microscopy. In vivo and in vitro, the expression of killer molecules in NK cells was analyzed by flow cytometry (FCM). And the invasiveness of trophoblasts was tested by Cell invasion assay. Results: Compared with normal abortion patients, the level of autophagy in the villi of RSA patients was significantly decreased. In vitro experiments indicated that co-culture with autophagy suppression of trophoblasts (3-MA-pretreated trophoblasts) increased cytotoxicity of NK cell, which was mediated by the upregulation of insulin-like growth factor-2 (IGF-2). Meanwhile, autophagy suppression of trophoblasts led to a low level of Paternally Expressed Gene 10 (PEG10), leading to impaired cell invasion. In addition, NK cells educated by autophagy-inhibited trophoblasts further decreased the proliferation and invasiveness of trophoblasts. Injection with 3-MA in vivo , the cytotoxicity of uterine NK cells in pregnant mice and the embryo absorption rate were significantly increased. Conclusion: Autophagy suppression of trophoblasts should increase the cytotoxicity of NK cells and damage the trophoblasts invasion possibly by targeting IGF-2 and PEG10, respectively, which ultimately leads to miscarriage.