The invention relates to a synthetic method of organic functional mesoporous silicon oxide. The method comprises the steps of coupling an organic functional group to ordered mesoporous silicon oxide through a copolymerization method in one step in an acidic condition to obtain the organic functional mesoporous silicon oxide, the functional degree of which is far greater than the grafting rate of a conventional copolymerization method, by taking triethoxy silane and tri alkoxy organic silane coupling agents as a silicon source and a polyethylene oxide-polypropylene oxide-polyethylene oxide triblock copolymer (P123) as a surfactant. In a reaction process, by controlling the proportion of adding amount of the organic silane coupling agent and triethoxy silane, the functional degree of the mesoporous silicon oxide and the degree of order of ducts can be regulated.