Hexavalent chromium (Cr(VI)) contamination in wastewater is a serious environmental threat. Cr(VI) removal is often interfered by antibiotics in wastewater, however, the underlying mechanism remains unclear. Here, molybdenum disulfide/montmorillonite (MoS2@Mt) composites were prepared and used for Cr(VI) removal to reveal the adsorption behavior of Cr(VI) on MoS2@Mt induced by sulfamethoxazole. The induction effect of the typical antibiotic sulfamethoxazole (SMX) was investigated. The adsorption capacity of MoS2@Mt was maximum at pH 2 and decreased with increasing pH. The performance results showed that SMX promoted Cr(VI) removal, with a maximum increase of 14.80 % in removal efficiency. Cr(VI) adsorption on MoS2@Mt followed the Langmuir model, whereas it was more consistent with the Freundlich model in the presence of SMX. This suggested that SMX induced a monolayer to multilayer shift in Cr(VI) adsorption. XPS results indicated that Cr(VI) removal pathways included Cr(VI) adsorption, chemical reduction of Cr(VI) to trivalent chromium (Cr(III)), and Cr(III) chelation. In particular, electrostatic pulling, coordinated adsorption, and hydrogen bond attraction contributed to Cr(VI) adsorption. Mechanism investigation suggested that Cr(VI) or SMX absorbed on the material surface continued to absorb SMX or Cr(VI) by electrostatic attraction, resulting in layer-by-layer adsorption behavior, which facilitated Cr(VI) removal. In actual wastewater treatment, MoS2@Mt reduced Cr(VI) concentrations (0.15–5 mg/L) to below the World Health Organization standard of 0.05 mg/L in the presence of 0.32 mg/L SMX. Overall, this study revealed the mechanism of SMX-induced Cr(VI) adsorption behavior, which favors the elimination of Cr(VI) from real complex wastewater.