The flowers of Abelmoschus manihot (L.) Medic is a traditional Chinese medicine used for the treatment of ischemic diseases. The present study is to investigate whether total flavones (TA) of extracted from Abelmoschus manihot L. Medic has the potential cardioprotective effect on myocardial ischemia/reperfusion (I/R) damage in rats. The index of myocardial injury, inflammatory biomarkers and NLRP3-related parameters were measured, respectively. The results demonstrated that compared to I/R group, TA reduced myocardial infarction area, declined serum creatinine kinase (CK), lactate dehydrogenase (LDH) levels, attenuated serum interleukin-6 (IL-6), IL-1β and tumour necrosis factor (TNF-α) production. Moreover, TA markedly enhanced the activities of superoxide dismutase (SOD) and reduced the amounts of malondialdehyde (MDA) in I/R rats. In addition, TA reduced myocardial I/R induced injury in rats by inhibiting NLRPR3 inflammasome. Thus, it is assumed that TA could significantly improve myocardial I/R injury in rats partially through suppressing NLRP3 activtion.