A series of Cu-loaded biomass-derived activated carbon (Cu/AC) catalysts with various impregnation ratios were prepared by precursor impregnation (PI) and activated carbon impregnation (ACI) methods. N-2 adsorption-desorption, inductively coupled plasma, X-ray diffraction, X-ray photoelectron spectroscopy, transmission electron microscopy, etc., were used to investigate their physicochemical properties. The performance of catalytic wet air oxidation (CWAO) of phenol using O-2 as the oxidant was evaluated. The results demonstrated that the catalysts prepared by the PI method have higher specific surface area and Cu content. In the catalysts, Cu species coexisted with Cu2+ and (Cu+ Cu-0). The content of (Cu+ + Cu-0) in PI catalysts was higher, which was favorable for the formation of free radicals (O-2(-)center dot and HO center dot), and then improved the conversions of phenol and chemical oxygen demand. The PI catalyst prepared with an impregnation ratio of 3 exhibited the best catalytic activity for phenol oxidation. Meanwhile, the loss of Cu species was the main cause of catalyst deactivation.