Based on the Landau-Khalatnikov equation of motion, the switching dynamic behaviors, (including the average polarization, switching time, switching current and coercive field) of a ferroelectric bilayer film with a surface transition layer within each constituent thin film and a ferroelectric interfacial coupling between two thin films have been investigated. Results reveal that there is a competitive mechanism in the bilayer film, the action of surface transition layer and the interfacial coupling. The abnormal behavior is discovered in the polarization reversal process of the bilayer film, which can be attributed to the competition between the surface transition layer and the interfacial coupling. The combined action of surface transition layer and interfacial coupling plays a decisive role on the dynamic properties of a ferroelectric bilayer film.