It is a big challenge to construct proton-conductive materials for practical applications operating at high temperatures and low humidity. Herein, we propose an ionothermal strategy for the preparation of highly stable NH₂-MIL-53(Al)_it nanomaterials with high proton conductivity. The crystalline structure and the direct incorporation of the 1-ethyl-3-methyl-imidazolium ionic liquid within NH₂-MIL-53(Al)_it are identified by XRD, TG/DTA and IR techniques. The as-prepared NH₂-MIL-53(Al)_it exhibits a high proton conductivity of 3.0 × 10⁻⁵ S cm⁻¹ at 80 °C and low relative humidity of ∼26%.