A model was proposed and presented to calculate the field water utilization coefficient for border irrigation and assess the irrigation efficiency. It coupled one-dimensional zero-inertia model for the irrigation process with Richards's equation for infiltration. The Newton-Raphson method and the double sweep algorithm were adopted to numerically solve the model. The dynamic boundaries at the advance and the recession fronts were specially treated for convergence and stability. After being parameterized, the models' accuracy was demonstrated by comparing the simulations with experimental data. The result shows that the integrated model is reasonable and feasible.