1,2-Dichloroethane (1,2-DCE), a prevalent industrial and environmental contaminant, induces toxic encephalopathy through inhalation, leading to neurotoxic effects and inflammation-driven brain edema. Human umbilical cord mesenchymal stem cells (HUCMSCs) secrete bioactive factors, including miRNAs, proteins, and lipids via exosomes, exhibiting anti-inflammatory and immune-regulatory properties. However, their potential in treating 1,2-DCE-induced neuroinflammation and the underlying mechanisms remain unclear. This study investigates how HUCMSCs mitigate 1,2-DCE-induced neuroinflammation. We exposed SVG p12 cells to 1,2-DCE and assessed inflammatory markers and A1 astrocyte activation. Co-culturing these cells with HUCMSCs, we used RNA sequencing to analyze inflammatory modulation. Additionally, HUCMSCs were administered to CD-1 male mice post-1,2-DCE exposure, evaluating the reduction in A1 astrocyte inflammation via behavioral tests, molecular analyses, and tissue staining. Pre-treating HUCMSCs with exosome inhibitors and co-culturing them with 1,2-DCE-treated SVG p12 cells investigated miRNA transfer. Results showed that 1,2-DCE activated A1 astrocytes, leading to increases in interleukin-1β (IL-1β, 4.9-fold), tumor necrosis factor-α (TNF-α, 2.5-fold), complement 3 (C3, 2.1-fold), and glial fibrillary acidic protein (GFAP, 1.4-fold). HUCMSCs effectively reversed 1,2-DCE-induced A1 astrocyte inflammation, attenuating IL-1β, TNF-α, and A1 astrocyte activation. RNA-seq highlighted modulation of the erb-b2 receptor tyrosine kinase (ERBB) pathway via Ral-binding protein 1-associated Eps domain-containing 2 (REPS2). In vivo confirmation underscored these findings. Importantly, HUCMSC-derived exosomes, particularly miR-3064-5p, reversed 1,2-DCE-activated A1 astrocyte inflammation, suggesting therapeutic potential. Collectively, HUCMSCs alleviate 1,2-DCE-induced neuroinflammation via exosome-mediated miR-3064-5p secretion, targeting REPS2 to mitigate neuroinflammation. This study advances the understanding of their therapeutic roles and highlights HUCMSC exosomal miRNA transfer for treating 1,2-DCE-induced neuroinflammatory conditions.