Abstract: A catalyst, which comprises molecular sieves; a molecular sieve structure is at least provided with a one-dimension eight-membered annular small hole channel, wherein the diameter of a substance that may diffuse in the direction of the eight-membered annular channel is no less than 2.0 ?, and the diameter of a substance that may be accommodated in the molecular sieves is no more than 6 ?. The catalyst is used for a methanol- and/or dimethyl ether-to-propylene reaction, comprising causing methanol and/or dimethyl ether to make contact with a methanol-to-propylene catalyst to obtain propylene.