Background: Huanglian Jiedu decoction (HLJDD) is a classical herbal formula for treating inflammatory diseases with Traditional Chinese Medicine (TCM). However, the impacts of HLJDD on neuroinflammation and the precise mechanisms involved remain poorly understood. Purpose: In the present study, HLJDD was found to inhibit lipopolysaccharide (LPS) induced neuroinflammatory responses in BV2 microglia via regulating NLRP3 inflammasome activation. Methods: Anti-inflammatory activity was evaluated with ELISA assay and the polarization changes were observed using immunofluorescent staining. The levels of NLRP3 inflammasome activation were determined using qPCR and Western blotting. Results: The administration of HLJDD successfully countered LPS-induced neuroinflammatory responses by attenuating microglial activation and fostering a phenotypic conversion from the pro-inflammatory M1 to the anti-inflammatory M2. . Additionally, HLJDD treatment demonstrated inhibition of NLRP3 inflammasome activation. Conclusion: The findings of the present study may provide insights into how HLJDD could be a therapeutic drug for neuroinflammatory diseases associated with regulating NLRP3 inflammasome and microglial activation.