The non-Darcy unsteady seepage flow model containing moving boundary conditions in low-permeability reservoirs is highly nonlinear, and it is hard to obtain its accurate analytical solution. In this paper, the characteristics of the existence of threshold pressure gradient of the non-Darcy seepage flow is incorporated into the continuous equation, and then, the mathematical model of non-Darcy unsteady seepage flow is built, which can describe the characteristics of moving boundary in low-permeability reservoirs.However, it doesn’t contain any moving boundary conditions so as to be convenient for the numerical computation. The Douglas-Jones predictor-corrector method is masterly adopted to obtain the numerical solution of transient pressure of the model, and its accuracy is verified by the fixed-point iteration numerical method. Result analysis shows that the curve of transient wellbore pressure of the non-Darcy unsteady seepage flow model in low-permeability reservoirs is different from that of the classical Darcy seepage flow model.And, there is an inflexion in its curve. Before the inflexion, the moving boundary hasn’t arrived at the outer boundary with constant pressure yet, when the crude oil is produced by the elastic expansion of fluid and rock; after the inflexion, the moving boundary has propagated to the outer boundary with constant pressure, and the energy of the outer boundary with constant pressure is supplemented.