Esophageal cancer is one of the fatal cancers around the world. Dexmedetomidine (DEX) is widely used during anesthesia of esophageal cancer surgery. Nevertheless, the role of DEX in the progression of esophageal cancer remains barely known. The proliferation, apoptosis and metastasis of esophageal cancer cells were detected by 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, flow cytometry, transwell migration and invasion assays and Western blot assay. The expression of miR-143-3p was measured by quantitative real-time PCR in esophageal cancer tissues and cells. The binding sites between miR-143-3p and epidermal growth factor receptor pathway substrate 8 (EPS8) were predicted by Starbase online software, and the combination was verified by dual-luciferase reporter assay. The murine xenograft model was established using KYSE150 cells to verify the function of DEX in vivo. DEX inhibited the proliferation and metastasis while accelerated the apoptosis of esophageal cancer cells. The abundance of miR-143-3p was lower in esophageal cancer tissues and cells than that in paring normal tissues and normal esophageal mucosal cells Het-1A. MiR-143-3p could be induced by DEX treatment in esophageal cancer cells, and miR-143-3p also suppressed the development of esophageal cancer. EPS8 was a functional target of miR-143-3p, and it played an oncogenic role in esophageal cancer. DEX inhibited the growth of tumor via miR-143-3p/EPS8 in vivo. DEX suppressed the growth and metastasis while facilitated the apoptosis of esophageal cancer cells through upregulating the abundance of miR-143-3p and reducing the level of EPS8 in vivo and in vitro, providing promising target for the treatment of esophageal cancer.