The invention relates to a shaping method of special channel wideband service wave beam, and a relative device, wherein the method uses user target direction as center, uses angle distance to form a plurality of narrow service beams, to be weighted and layered to synthesize wide service beam. The device comprises an antenna array, a multi-path amplifier, a multi-path receiving/sending signal machine, an ascending reach angle evaluation and base band processor, a descending wideband beam shaping weighting value generator, and a descending beam shaping unit. The invention can effectively improve beam width, which only stores the shape weighting values of one group of general narrow service beams with different directions, without differentiating different antenna states, with easy application, reduced the effect of narrow beam width on the property of intelligent antenna property, improved system stability and reliability.