The invention discloses a broadband phase-only emission self-adaptive beam forming method. The method comprises the following steps: firstly, designing a sub-band filter bank; utilizing an analysis filter bank in the sub-band filter bank to complete sub-band division of the broadband signal; next, calculating a phase-only adaptive beam forming weight vector of each sub-band by combining a sub-bandMLCMV criterion and a RUWO algorithm; and finally, reconstructing the processed broadband signal by using a comprehensive filter bank in the sub-band filter bank. Simulation experiment results show that the phase-only weighting algorithm studied by the invention can control the zero-point direction of the directional diagram of the broadband transmission signal antenna not to change along with the frequency only by adjusting the phase, and engineering realization is easier. The interference zero depth can be improved and the interference suppression performance can be enhanced by dividing narrower sub-bands.