This article reports a new catalyst deactivation model for residue hydrotreating technology (RHT) with three adjustable parameters, named as "active-region-migration model". The active-region-migration model is proposed to describe the catalyst deactivation of RHT where the catalysts are deactivated due to metal loading. Along with the lumped reaction kinetics, the deactivation model can be applied to simulate the hydrogenation reaction performance in RHT. Industrial data from a commercial RHT unit show reasonably good agreements with the model calculations. Essentially, the active-region-migration model can separately simulate the catalytic-activity- change of each hydrogenation reaction during the whole run of RHT, with a single curve.