The impacts of high-frequency application of digital filter initialization schemes on the simulation of Typhoon In-fa in the hourly cycling assimilation system are studied using the mesoscale model WRF (Weather Research and Forecasting). The main results are as follows. (1) The digital filtering can generate filtering increments related to weather phenomena. In the clear sky area, the physical process such as radiation is closed during the backward integration, the near-surface temperature changes mildly at the end of backward integration, and during the forward integration, the downward shortwave radiation accumulates exceedingly at the surface in the daytime, while the surface emits much heat radiation in the nighttime, therefore, the 2-m temperature rises in the daytime and falls in the nighttime. In the convection area of typhoon, considering that the backward integration is adiabatic, the rainfall from the air mass during the original ascending motion with vapor condensation and latent heat release cannot absorb heat and become water vapor in the adiabatic sinking and warming. The heat abnormally accumulates and water vapor decreases during the backward integration, resulting in the change of thermal structure in the strong convection area. (2) The statistical results show that with the increase of the frequency of digital filtering, the impacts of initialization on initial field and prediction increase, and the caused prediction differences remain in the whole simulation process. (3) By applying several times of digital filter initialization on the basis of cycling assimilation, digital filtering initialization can suppress high-frequency noise. The reason is that after multiple filtering, the typhoon intensity increases due to the strengthening of the warm core of the typhoon circulation center, and the minimum pressure is more close to the best track data; the weakening of warm and humid air transport to the south of Shandong Province results in the severe rain’s missing alarm in the province’s southeastern part; the southerly position of the typhoon circulation affects the time of its combining with the westerly trough, leading to the lower moving speed in the later period.