The invention provides a method for combining a yellow fluorescent powder used for a white light LED and belongs to the preparation technique of rare earth fluorescent powders. The chemical formula thereof is (Y1-x-yMyCex)3Al5O12, wherein M is one chosen from Tb, Gd, Sm and Yb, x is more than or equal to 0 but less than or equal to 0.1 and y is more than or equal to 0 but less than or equal to 0.1. The method comprises the following steps of: weighting yttrium salt, M salt, cerium salt, aluminum salt according to the element measurement and a defined amount of surface active agent and fluxing agent, fully mixing the reactants, the surface active agent and a defined amount of ligand, ball-milling while adding proper lubricant, filtering, washing and drying so as to acquire a precursor, mixing the precursor with the fluxing agent, and burning in a reducing atmosphere so as to acquire the needed fluorescent powder. The method for combining the fluorescent powder of the invention has the advantages of low burning temperature, short time, high production efficiency, small grain size, narrow distribution, excellent lighting performance and capable of being efficiently aroused by the blue light LED chip.