The invention relates to a treatment method of a rhodium catalyst sample used in the acetic anhydride synthesis technology and containing amine ligand before that the rhodium content of the sample is determined by using the spectrophotometry, belonging to the technical field of sample treatment in spectrophotometry. The sample treatment comprises three steps: 1. taking right amount of samples into a beaker, adding 20% sodium acetate, heating on the sandbath to lead the solution in the beaker to be evaporated to dry; 2. adding chloroazotic acid or nitric acid in the beaker and heating on the sandbath to lead the solution in the beaker to be evaporated to dry; and 3. washing and transferring: washing the beaker for more than 5 times by distilled water, transferring the cleaning solution to a volumetric flask, and then determining the rhodium content by the spectrophotometry. The determining result is satisfactory after the sample is treated by the method.