SPAO-5 molecular sieve is a kind of microporous silicoaluminophosphate molecular sieve with one-dimensional pore structure as the basic unit of twelve-membered ring composed of PO4, AlO4, SiO4 tetrahedron alternately. The framework is negatively charged, with cation exchange capacity and adjustable surface acidity. Because of its special structure of AFI, SAPO-5 molecular sieve has great applications in the fields of shape-selective catalysis, adsorption and separation, photochemical conversion, nonlinear optical material preparation, carbon nanotube preparation, air pollution control and catalyst support. It is often used in the cracking reaction of heavy oil; the alkylation reaction of toluene, biphenyl, etc.; the reaction of aromatic compounds; the isomerization reaction of n-butane; the desorption of hydrocarbons from automobile exhaust, etc.