Only in the presence of sidelobe jamming(SLJ),can the conventional adaptive monopulse technique null the jamming effectively and maintain the monopulse angle estimation accuracy simultaneously.While mainlobe jamming(MLJ) exists,the mainlobe of adaptive pattern will subject to serious distortion,which results in a failure of detecting and tracking targets by monopulse technique.Therefore,a monopulse angle estimation algorithm based on combining sum-difference beam and auxiliary beam is presented.This algorithm utilizes both high gain difference beams and high gain auxiliary beams for cancelling the mainlobe jammer and multiple sidelobe jammers(SLJs) while keeping an adaptive monopulse ratio.Theoretical analysis and simulation results indicate that the serious invalidation of monopulse technique in MLJ and SLJs scenarios is resolved well,which improves the monopulse angle accuracy greatly.Furthermore,the proposed algorithm is of simple implementation and low computational complexity. Only in the presence of sidelobe jamming (SLJ), can the conventional adaptive monopulse technique null the jamming effectively and maintain the monopulse angle estimation accuracy simultaneously. Whilst mainlobe of adaptive pattern will subject to serious distortion, which results in a failure of detecting and tracking targets by monopulse technique. Before, a monopulse angle estimation algorithm based on combining sum-difference beam and auxiliary beam is presented. This algorithm utilizes both high gain difference beams and high gain auxiliary beams for canceling the mainlobe jammer and multiple sidelobe jammers (SLJs) while keeping an adaptive monopulse ratio. Theoretical analysis and simulation results indicate that the serious invalidation of monopulse technique in MLJ and SLJs scenarios is resolved well, which improves the monopulse angle accuracy greatly. Futurertherm, the proposed algorithm is of simple implementation and low computational complexity.