The invention discloses a method for combined production of benzyl alcohol, benzaldehyde and benzoic acid through oxidizing toluene. The method comprises the following steps: 1, oxidizing: continuously introducing toluene, a catalyst and an oxygen-containing gas to an oxidation reactor, and reacting to obtain an oxidation reaction solution; 2, hydrolyzing: continuously introducing the oxidation reaction solution to a hydrolysis reactor, continuously adding water to the hydrolysis reactor, and reacting to obtain a hydrolysis reaction mixture; 3, carrying out liquid-liquid layering: continuously adding the hydrolysis reaction mixture to a liquid-liquid layering device to obtain an upper layer oil phase containing toluene, benzyl alcohol and benzaldehyde and a lower layer water phase containing benzyl alcohol, benzaldehyde and benzoic acid; and 4, carrying out product separation: rectifying the upper layer oil phase to obtain incompletely reacted toluene, benzyl alcohol and benzaldehyde products, and cooling and crystallizing the lower layer water phase, and filtering the cooled and crystallized lower layer water phase to obtain a filtrate and a benzoic acid product. The method has the advantages of high raw material conversion rate, few byproducts, good selectivity of target products, and environmental protection.