As an important chemical intermediate, benzaldehyde is widely used in the fields of medicine and fine chemicals. In order to solve the problem of pollution in the traditional benzaldehyde synthesis , the preparation of benzaldehyde by catalytic oxidation of benzyl alcohol has high research value and praetical significance. In this study, a cerium-modified algal-derived biochar catalyst with excellent catalytic oxidation performance was prepared. The physico-chemical properties of the catalysts were thoroughly analyzed by various characterization means, such as scanning electron microscope, X-ray dilractometer, and X-ray energy spectrometer. The effects of reaction temperature, oxidation reaction time, doping with CeO2 and catalyst dosage on benzyl alcohol conversion and benzaldehyde selectivity during catalytic oxidation were further investigated through controlled variable tests. The results showed that the prepared catalysts could realize the efficient conversion of benzyl alcohol under mild conditions, and the conversion of benzyl aleohol and selectivity of benzaldehyde was 100% and 86.59%, respectively. This study realizes the high selective conversion of benzyl alcohol to benzaldehyde under mild conditions, and proposes an alternative for the preparation of benzaldehyde in a green, economic and environmentally friendly way.