Abstract: Wideband adaptive beamformer (WABF) has better spatial resolution and much better interference rejection capability than conventional delay-and-sum (DAS) beamformer, but the performance of WABF decreases severely in real condition due to the array amplitude-phase response error and the array steering vector ( ASV) error. In this paper, a wideband robust beamforming method based on steered minimum variance (STMV) method is proposed. The ellipsoidal ASV uncertainty sets in narrowband robust Capon beamforming (RCB) are extended to WRB method. Simulation results show that WRB could realize the weak signal of interest (SOI) detection in strong sidelobe jamming and ASV error environment; maintain the SOI output in amplitude-frequency error condition. Besides, the requirement of snapshots is lower than STMV method.