In order to describe the mechanism and characteristics of enhanced liquid production in heterogeneous reservoirs, and based on the traditional black oil model, a three-dimensional, three-phase mathematical model, which takes threshold pressure gradient into account, is put forward. And, a corresponding numerical simulator is developed, in which the Implicit Pressure Explicit Saturation Method is used. Through establishing the conceptual models, the influences of permeability ratio (the ratio of highest permeability to lowest permeability), the amplitude and time of enhanced liquid production, and the initial liquid production rate are studied. The results show that: under certain amplitude of enhanced liquid production, the development effect of enhanced liquid production becomes worse with the increase of permeability ratio. The development effect of enhanced liquid production gets better while the amplitude of enhanced liquid production increases. The earlier of enhanced liquid production, the better development effect is. When the initial liquid production rate is larger, the development effect of enhanced liquid production for the model with larger permeability ratio is better.