Aiming at the case of two jamming sources, a new method of main-lobe jamming suppression and target angle parameter estimation was presented for missile-borne mono-pulse high-repetition stepped-frequency radar application. In this method, beam-forming in modified azimuth-elevation coordinate system was done in order to obtain separable pattern function; eight channels, including sum, azimuth-difference, elevation-difference and other auxiliary channels, were constructed by the use of digital processing of sub-array output signals; and modified sum channels and modified difference channels were formed by using multi-channel cancellation technology. This method can suppress main-lobe jamming and meanwhile preserve undistorted mono-pulse ratio. Theoretical analysis and simulation results have proved its effectiveness.