The invention relates to a method for preparing aldehyde ketone by catalyzing carbon-carbon double-bond oxidative cleavage and belongs to the technical field of chemistry and chemical engineering. Particularly, reaction is conducted at a temperature of 30 to 120 DEG C for 1 to 48 hours by taking nitroxide free radical and iron salt as catalysts and air or oxygen as an oxygen source, so that carbon-carbon double bonds (as shown in the description) can be oxidized and broken into corresponding aldehyde or ketone. The system provided by the invention has various advantages of high catalytic activity, high selectivity, mild condition and the like.