The invention provides a method for leaching platinum metals from an automobile tail gas spent catalyst by microwave heating and melting, comprising the steps of: crushing and finely grinding the automobile tail gas spent catalyst, uniformly mixing sodium bisulfate serving as a leaching agent with the automobile tail gas spent catalyst, and heating under microwave at the temperature of 300-700 DEG C for 30-150min to obtain sinter; and leaching under water dissolving and stirring at normal temperature for 10-60min, carrying out solid-liquid separation, washing filter residue three times, discarding the filter residue, collecting filtrate and cleaning solution to obtain the solution rich in platinum metals Pd and Rh. According to the method, microwave heating is adopted to simultaneously leach Pd and Rh, the leaching rate of platinum metal Pd reaches 99.97%, the leaching rate of platinum metal Rh reaches 98.91%, and both the leaching rates are improved as compared with that of single wet method or pyrogenic process leaching; and the leaching process is simple, the process flow is short, the reagent is single, the reagent consumption amount is low, the solution contains few impurity elements, the leaching rate is high, the leaching time is short and the energy consumption is low, so that the method has wide industrial application prospects.