The invention relates to a solvent-free green ammoximation process based on membrane distribution with a procedure as: adding TS-1 catalyst and ketone into a reactor in advance; setting the stirring speed and reaction temperature; after reaching the set temperature, adding a certain amount of ammonia and hydrogen peroxide into a reaction solution, wherein the hydrogen peroxide is fed in a way of using membrane as a distributor, the ammonia is fed in a continuous or semi-continuous manner; oxime is produced upon the reaction. The advantages of the invention include the mild reaction conditions, high reacting efficiency, simple operation and environmentally-friendly process. And there is no need to add any solvent during the reaction process. During the ammoximation reaction, both the conversion rate of the ketone and the selectivity of the oxime can be over 98.0%.