In this study, the soil around a granular column is considered as a drain influence zone, in which horizontal permeability coefficient changes linearly with radial distance. And so, it is only a special case that the soil around a column is traditionally divided into smeared and undisturbed zones with constant horizontal permeability coefficient. The differential governing equations are established on the basis of gradual change in horizontal permeability of soft soil caused by disturbance during granular column installation, and the analytical solution is obtained and then applied to investigate the influence of the permeability change on the consolidation behavior. It shows that the influence of disturbance on consolidation is significant. The greater the disturbance is, the slower the consolidation is.