In this work, titanium dioxide surface modified montmorillonite (TMC) were prepared by sol–gel method, so as to improve its selective adsorptivity for trivalent chromium ions (Cr³⁺). When it was applied to remove low concentration of Cr³⁺(10 mg/L) from wastewater, the remaining concentration of Cr³⁺ was less than 1.5 mg/L, meeting the emission standard required by the Chinese Environmental protection agency (GB4287-92). The phase, structure and morphology of TMC were determined by means of XRD, CEC, IR, Raman, XPS, SEM, TEM and BET. It was found that titanium dioxide (TiO₂) was uniformly dispersed on the surface of montmorillonite (MMT), and the spacing of MMT layer was almost unchanged via filling with Na⁺, so that the selective adsorptivity of MMT for Cr³⁺ was achieved. At the same time, theoretical calculations based on first principles and density functional theory confirmed the adsorption selectivity of MMT for Cr³⁺. In addition, the structural advantages of TMC addressed the shortcomings of MMT surface negative potential that it could not perform adsorption selectivity. Moreover, the adsorptive process of Cr³⁺ with TMC followed the pesudo-second-order kinetic equation, and Langmuir equation could better describe the adsorption mechanism (the maximum adsorption capacity was 194.1 mg/g). After five cycles, the removing efficiency was still over 89%. Therefore, TMC accompanied with high selective adsorptivity, simple synthesis process, as well as high regenerative performance, had great potential for removing low concentration of Cr³⁺ from wastewater.