The invention relates to a method for preparing p-bromophenylacetone by biomimetic catalytic oxidation of p-bromoethylbenzene, comprising the following steps of: taking p-bromoethylbenzene as raw material; selecting either of 1-30ppm mononuclear metal porphyrin and mu-oxo-dinuclear metal porphyrin or the both as a catalyst; introducing oxygen at the flow speed of 10 to 60mL/min under normal pressure without solvents; initiating reaction at 140 DEG C to 170 DEG C; and reacting for 6 to 16h at 80 DEG C to 120 DEG C to obtain the p-bromophenylacetone. The method uses the mode of high-temperaturequick initiation and low-temperature reaction, greatly shortens the initiation time of the reaction and the reaction time, improves the reaction efficiency, reduces the energy consumption and operation costs and improves the reaction safety.