Abstract: Capon beamformer of acoustic vector sensor array is extremely sensitive to slight array errors.The norm of steering vector is constrained by using Lorentz Cone Programming to improve the robustness.Catering to the characteristic that pressure component and velocity component of an acoustic vector sensor can be influenced in different degrees by array errors,"dual-line constraint" is adopted.The problem of norm-constraint beamforming can be converted to the form of Lorentz Cone Programming,and solved by interior point method.The result of stimulation proves that noises restraint of the present approach is greater than conventional beamformer and its robustness is better than Capon beamformer.