The anomalous Hall effect (AHE) of perpendicular ferromagnetic materials has gained extensive attention in spintronics applications. The high annealing stability of the AHE is of fundamental and technological importance. Herein, we describe the realization of the high annealing stability of the AHE by introducing Ta2O5 interfacial layer in perpendicular Co/Pt multilayers. The X-ray photoelectron spectroscopy analysis reveals that the O out-diffusion from CoO is mainly responsible for the good annealing stability of the AHE.