A multiple-relaxation-time (MRT) lattice Boltzmann (LB) model is developed for simulating double-diffusive convection in porous media at the representative elementary volume scale. In the model, the equilibrium moments of the temperature and concentration distributions have been modified, which makes the effective thermal diffusivity and heat capacity ratio as well as the effective mass diffusivity and porosity decoupled. Numerical tests demonstrate that the present model can serve as an accurate numerical method for simulating double-diffusive convection in porous media. (C) 2018 Elsevier Ltd. All rights reserved.