This study developed a migration model, termed the inter-city migration model (IcMM), based on the “push-pull” theory to model China's inter-city population migration. The IcMM is comprised of three sub-models: the pull, push, and distance impedance models. The IcMM simulates two-way inter-city migration based on cities' pull factors, push factors, and distance impedance. The IcMM is a strict implementation of the “push-pull” theory. Model verification shows that it can achieve good results in simulating China's inter-city migration. The three sub-models included in the IcMM are loosely coupled and easy to expand. The regional applicability and extension of the proposed model is also discussed.