Abstract: In order to solve the problem that radio frequency interference(RFI) deteriorate the performance of high frequency surface wave radar (HFSWR) significantly, this paper analyzes the difference of characteristic in radar echoes and range-Doppler(RD) figure between RFI and target signals, estimates the frequency and DOA reference to MUSIC algorithm and uses subspace projection methods to decompose RFI signals and useful target echo signals on DOA and frequency, then subtracts radio frequency interference components from the original signals in order to achieve the RFI suppression. We can conclude that the algorithm can effectively suppress RFI by analyzing simulation results and measured data processing results.