Sample digestion methods of automobile catalysts were researched, based on a certain ratio of hydrochloric acid, nitric acid, hydrofluoric acid, perchloric acid and sulfuric acid. The content of Pt, Pd and Rh in samples was determined by UV spectrophotometry. The results show that the digestion method with hydrochloric acid, hydrofluoric acid and hydrogen peroxide and adopting a polytetrafluoroethylene (PTFE) digestion tank, is more beneficial to the digestion of Pt, Pd and Rh. The recovery rates of Pt, Pd and Rh are 99.5%, 99.8% and 101.6%, respectively. The relative standard deviation is 3.04% for Pt, 2.71% for Pd and 1.80% for Rh. The method is simple and the result is satisfactory.