The invention relates to a catalyst for preparing acrylonitrile through propylene ammonia oxidation and a preparation method thereof. The catalyst mainly solves the problems of low selectivity and poor stability of a catalyst used for propylene ammonia oxidation reaction in the prior art. The catalyst has the scheme that the catalyst for producing acrylonitrile through propylene ammonia oxidation comprises a carrier and active ingredients expressed by the following general formula: AaBbCcBidMo<13.6>Ox, in the formula, the A is selected from at least one kind of materials from K, Rb and Cs; the B is selected from at least one kind of materials from Ca, Mn, Fe, Co, Ni, Mg, Cr, W, P and Nb; the C is selected from at least one kind of materials from rare earth elements; the carrier comprises silicon dioxide and carrier modifiers; the carrier modifiers are selected from at least one kind of materials from aluminum oxide and diatomite. The problems are better solved, and the catalyst can be used for industrial production of producing acrylonitrile through propylene ammonia oxidation.