The invention discloses a preparation method of an aluminum tin phosphate molecular sieve catalyst, and belongs to the field of chemical engineering, the catalyst is prepared by the following steps: mixing a phosphorus source, an aluminum source, a tin source, a structure-directing agent and a solvent in proportion, placing in a hydrothermal reaction kettle, aging for 0-5 hours, then carrying out microwave crystallization at 160-220 DEG C for 1-8 hours, after the crystallization is finished, filtering, washing and drying the product, and roasting at 300-900 DEG C for 2-6 hours to obtain the aluminum tin phosphate molecular sieve catalyst. The aluminum tin phosphate molecular sieve catalyst is obtained; the catalyst is used for rosin resin acid oxidation reaction, and is simple in process method, low in cost, excellent in thermal stability, good in catalytic effect and easy to recover.