We report the observation of the antisymmetric magnetoresistance (MR) in perpendicular magnetized CoTb films with inhomogeneous magnetization distribution driven by gradient magnetic field. By synchronously charactering the domain pattern evolution during transport measurements, we demonstrate that the nonequilibrium currents in the vicinity of tilting domain walls give rise to such anomalous MR. Moreover, theoretical calculation and analysis reveal that the geometry factor of the multidomain texture plays a dominant role in generating the nonequilibrium current. The explicitly established interplay between the anomalous transport behaviors and the particular domain wall geometry is essential to deepening understanding of the antisymmetric MR, and pave a new way for designing novel domain wall electronic devices.