With the continuous improvement of radar performance, it is very difficult to break through the enemy's radar defense net by relying solely on trajectory planning. In actual penetration, fighters use a variety of electronic jamming methods to achieve penetration. Based on the dynamic changes of RCS, this paper model the discovery probability of penetration fighters under active jamming and passive jamming respectively, and studies the factors that affect the penetration probability and survival rate of fighters under different jamming situations. By comparing the radar detection probability with and without jamming, it is concluded that the fighter's active and passive jamming can effectively reduce the radar detection probability. This article has certain guiding significance for the fighter's dynamic penetration.