In this study, we provide an insight into the polarization switching behavior of HfO2-based ferroelectric field-effect transistors (FeFETs) by utilizing the Landau-Ginzburg-Devonshire model in the multiscale physics-based modeling platform GinestraTM. Simulation results showed that a sufficient trap density is needed for complete polarization reversal. After that, we characterize the charge-Trapping behavior with a dedicated experiment. The test results are then compared with the simulation results under the same test condition. The charge trapping behavior is more sensitive to applied voltage amplitude than to the pulse width. From the simulation, we could also see that the potential difference between the applied gate voltage and the channel potential at the onset of strong inversion remains constant for all gate voltages.