OBJECTIVE To investigate the mechanism of Pangshi antai zhixue decoction in the improvement of spontaneous abortion with heat syndrome by regulating the NOD-like receptor protein 3 （NLRP3） inflammasome. METHODS The binding activities of 13 main components in Pangshi antai zhixue decoction with NLRP3， apoptosis-associated speck-like protein ， containing a CARD （ASC）， and caspase-1 precursor （pro- No.20-21ZY1053） caspase-1） were predicted by molecular docking. Sixty 1-day-old pregnant rats were randomly divided into normal group， model group， dexamethasone group （0.002 g/kg）， and Pangshi antai zhixue decoction low-， medium-， and high-dose groups （11.025， 22.05， 44.10 g/kg）， with 10 rats in each group. Each group was given distilled water/corresponding medicinal solution intragastrically， once a day， for 12 consecutive days. Except for normal group， other groups were given traditional Chinese medicine for warming yang and mifepristone to establish a model of spontaneous abortion with heat syndrome. 24 h after the last medication， serum levels of triiodothyronine （T3）， thyroxine （T4）， interleukin-2 （IL-2）， IL-4， IL-6， IL-10， and interferon-γ （IFN-γ） were all detected； the abortion rate and uterine coefficient were calculated； the pathological morphology of the pregnant uterus was observed； protein expressions of NLRP3， ASC and caspase-1 were detected. RESULTS The molecular docking results showed that the binding energies of 13 main components of Pangshi antai zhixue decoction with NLRP3， ASC， and pro-caspase-1 were all less than －5 kJ/moL. The animal experiment results showed that compared with normal group， the uterine coefficient and serum levels of IL-4， IL-6 and IL-10 were decreased significantly in model group （P＜0.05）； the abortion rate and serum levels of T3， T4， IL-2 and IFN-γ as well as protein expressions of NLRP3， ASC and caspase-1 were increased significantly （P＜0.05）； there were abortion lesions in the pregnant endometrium. Compared with the model group， most of the quantitative indicators mentioned above were significantly reversed in Pangshi antai zhixue decoction groups （P＜0.05）， and the endometrial miscarriage lesions in pregnancy were improved to varying degrees. CONCLUSIONS Pangshi antai zhixue decoction influences the immune balance between mother and fetus by regulating the formation of NLRP3 inflammasome， down-regulating pro-inflammatory cytokines such as IFN-γ and IL-2， and up-regulating anti-inflammatory cytokines such as IL-4， IL-6 and IL-10， thereby improving spontaneous abortion with heat syndrome.