Hyperoside (HYP) is the principle active component of Crataegus pinnatifida. Thymic stromal lymphopoietin (TSLP) plays a vital role in the pathogenesis of allergic reactions. Here, we investigated how HYP regulates the levels of TSLP in a human mast cell line, HMC-1 cells. We analyzed the levels of TSLP by treatment with HYP in phorbol myristate acetate plus calcium ionophore A23187-stimulated HMC-1 cells with ELISA and a polymerase chain reaction analysis. We also analyzed the pathway that HYP regulates TSLP by measuring the level of fluorescent intracellular calcium and using a Western blot analysis. HYP decreased the level of intracellular calcium in stimulated HMC-1 cells. It also significantly decreased the production and mRNA expression of TSLP in stimulated HMC-1 cells. It significantly decreased the levels of receptor-interacting protein 2 and active caspase-1 in stimulated HMC-1 cells. HYP significantly decreased the translocation of NF-κB into the nucleus and degradation of IκBα in the cytoplasm in stimulated HMC-1 cells. Furthermore, it significantly decreased the production and mRNA expression of interleukin-1β and interleukin-6 in stimulated HMC-1 cells. Taken together, our findings establish HYP as a potential agent for the treatment of allergic reactions.