Abstract: This paper proposes a design approach of wide-band constant beamwidth beamformer based on second-order cone programming(SOCP),considering the fact that the operating frequency bandwidth is narrow,when conventional beamformer applied to constant beamwidth beamforming.The approach includes: first,The working frequency band is divided into several narrow-band frequency range,second,make each sub-band beam on the center frequency get the best approximation of expect beam based on SOCP,to achieve the corresponding weight vector,and the main lobe of the beam of each sub-band center frequency constant.The results of computer simulation show that the method of improving wide-band beam based on SOCP is robust.