Abstract: Modern battlefield electromagnetic confrontation is increasingly complex, and there are many kinds of electromagnetic interference. The interference will form the main-lobe interference when it comes into the receiver main-lobe. Traditional anti-interference method in space polarization and time-frequency domain is hard to suppress the main-lobe interference. And the performance of radar is affected severely. Aimed at the problem of main-lobe interference suppression, space-polarization filtering method based on multi-base radar is developed. It takes advantage of the difference of target polarization scattering characteristics in different scattering angles. Firstly proposed method suppresses side-lobe interference and spatial noise in space domain using main-lobe shape preserving technique. Then calibrate time delay and calculate the covariance matrix of data including main-lobe jamming and echo signal. Then recognize main-lobe jamming in space-polarization signal space through the decomposition of covariance matrix, and estimate echo signal steering vector. Finally acquire target echo signal by multi-base space-polarization filtering. The main-lobe interference is filtered in echo signal subspace and echo is remained. Through simulation of suppressing noise and repeater interference, it proves that proposed method can suppress main-lobe interference effectively, and enhance output signal to interference and noise radio.