The invention discloses a method for determining heavy metal content in building materials by applying an X-fluorescence melting method. The method comprises the following steps: drying a to-be-determined sample at 105+/-5 DEG C until the weight is constant, placing the dried sample into a dryer, and cooling to room temperature for later use; burning the whole crushed to-be-determined sample by use of a square-hole sieve of 45 microns until the weight is constant; adding a fluxing agent into a test sample after ignition loss, mixing fully, then adding a demoulding agent, and placing the mixture into a high-frequency melting sample furnace, warming to the required temperature for 3-4 minutes, casting a mold, and demolding, thereby obtaining a melting sheet; analyzing the sample melting sheet by utilizing an X-fluorescence spectrophotometer, and calculating the heavy metal content in the building materials. The method provided by the invention is rapid and accurate, can be used for reducing the detection cost, and improving the inspection efficiency greatly.