Impacts of multiple application of digital filter initialization scheme was studied by numerical experiments with the mesoscale model WRF on Typhoon INFA in the hourly cycle assimilation system. The main results are as follows: The filter can generate filtering increments related to weather. In the clear sky region, affected by the fact that the physical process such as radiation processes is closed, At the end of backward integration the near-surface temperature changes little, during the forward integration, the downward short wave radiation flux at the surface over-accumulates in the daytime, the ground heat flux over-accumulates in the nighttime, caused the 2m temperature is increased in the daytime and 2m temperature reduction in the nighttime. In the strong convection typhoon region, affected by the fact that the backward integral is adiabatic, the precipitation that water vapor condenses away from the air mass during the original ascending motion with latent heat release cannot absorb heat and become water vapor, the abnormal temperature increased and water vapor decrease during the backward integration result in the change of the thermal structure of the initial convective area. The filtering increment keeps increasing with the increase of the number of digital filtering lead to the increasing of simulation differences. After the assimilation data was introduced, Digital filtering initialization can reduce high frequency noise. The reason is that after multiple filtering, the warm core of the typhoon circulation center increases and the typhoon intensity increases. The weakening of warm and humid air transport to southern Shandong resulted in the omission of heavy rain report in southeastern Shandong. The southerly position of the typhoon circulation affected the time of combining with the westerly trough in the late period, resulting in moving slow in the late period.