Objective To study the effects and mechanisms of Smilax glabra flavonoids ( SGF) on myocardial hypertrophy and cardiac inflammation induced by isoproterenol ( ISO) in mice. Methods C57 / 6J mice were randomly divided into a normal group, ISO model group (1. 25 mg / ( kg·d)), SGF low-dose group (50 mg / ( kg·d)), and SGF high-dose group (100 mg / ( kg·d)). The SGF groups were given prophylactic SGF for 7 days before modeling, then subcutaneous ISO injection was given to each group, and echocardiography was performed after continuous injection for 7days. Serum was separated from orbital blood, and the NT-proBNP and inflammatory factor ( IL-1β, IL-6, and TNF-α) contents of the blood were detected. Myocardial specimens were collected, and pathological changes to myocardial tissue were observed. Myocardial ROS levels were detected by DHE staining. The mRNA levels of heart-related hypertrophy genes and changes in the expression of key proteins in the inflammatory pathway of NLRP3 / Caspase-1/ IL-18 in myocardial tissue were detected. Results SGF prophylactic administration decreased IVSd, IVSs, and EF in echocardiography and increased LVIDs, LVIDd, and LVESV. The IL-1β, IL-6, TNF-α, and NT-proBNP contents of blood decreased, and the mRNA expression levels of the heart-related hypertrophy genes for ANP, BNP, and β-MHC were subdued. The increase in myocardial ROS levels was also inhibited. The protein expression of NLRP3, Caspase-1 (p20), and IL-18, which are key factors in the NLRP3 / caspase-1/ IL-18 inflammatory pathway, was down-regulated in myocardial tissue. The hypertrophy and disordered arrangement of cardiomyocytes were improved, the increase in fibroblast numbers outside myocardial fibers was reduced, and the infiltration of inflammatory cells and fibrosis of myocardial tissue were alleviated. Conclusions SGF can improve ISO-induced myocardial hypertrophy and cardiac inflammation in mice and may act through the NLRP3 /Caspase-1/ IL-18 inflammatory pathway.