The invention discloses an oxidation sweetening method of diesel oil. In the method, after sulfur-diesel oil is oxidized, an absorption method is used for removing a polar-sulphide; wherein, in the adopted absorption device, two sorbent layers are adopted; wherein, the sorbent at the upper stream is active carbon and the sorbent at the down steam is amorphous silica-alumina. In the invention, thecharacteristics of the diesel oil after being oxidized and the polar-sulphide are combined; the proper active carbon and the amorphous silica-alumina are selected to be matched and used; the efficiency of the whole absorption device is improved, thus fully using the sorbents in the whole absorption device, increasing the sulfur allowance and simultaneously prolonging the running period of the device, reducing the exchange and regeneration frequency of the sorbents, improving the yield of the diesel oil and reducing the operation cost.