Abstract: Smart noise jamming based on digital radio frequency memory (DRFM) has both oppressive jamming effect and deceptive jamming effect, and is difficult to be effectively suppressed by traditional anti-jamming methods. In order to solve this problem, an anti-jamming method for linear frequency modulation (LFM) pulse compression radar system is proposed. The proposed Method is combined with fractional Fourier Transform (FrFT) and fractional domain filtering strategy. In this method, firstly the received signal is fractional Fourier transformed; then a filter is designed according to the characteristic of transmitting signal in the fractional domain; the received signal is filtered by the designed filter to eliminate jamming; lastly do fractional fourier inverse transformation to restore the target signal. The simulation results show that the method can effectively suppress two kinds of smart noise jamming: convolution noise jamming and multiplication noise jamming, and can accurately detect the position of the target.