A green synthesis method of p-chlorobenzaldehyde, an important fine chemical intermediate, was reported. p-Chlorobenzaldehyde was achieved through the catalytic oxidation of p-chlorobenzyl alcohol. Hydrogen peroxide and copper salt were used as oxidant and catalyst, respectively. The effects of the type and amount of copper salt, the amount of hydrogen peroxide, the dropping time and the reaction temperature on the yield of p-chlorobenzaldehyde were investigated. The optimum reaction conditions were obtained as follows: copper acetate was used as the catalyst, n[Cu(OAc)2] : n(p-chlorobenzyl alcohol) : n(H2O2) = 1 : 100 : 300, water as the solvent, reaction temperature and time were 96 ℃ and 2 h, respectively. The conversion rate was 93.1%, the selectivity for generating p-chlorobenzaldehyde was 97.7%, and the yield was up to 91.0%. The catalyst-containing water phase was recycled, and the yield could still reach above 85% after 5 cycles. The method has the advantages of green and environmentally friendly oxidant, recyclable catalyst and solvent, no waste acid production, which is suitable for industrial production.