The invention provides a method for preparing a white LED. The method of preparing the white LED comprises the steps of fixing an LED chip on a substrate arranged in an array; attaching a fluorescent film on the surface of the LED chip; making a mold corresponding to the substrate, arranging a projection corresponding to the size and shape of the surface of LED chip and for covering the surface of the LED chip onto the mold, and filling the mold with white glue slightly lower than the height of the projection; buckling the substrate fixed with the LED chip onto the mold, flipping the mold, and removing the mold after the white glue is formed at the periphery of the LED chip, baked and cured; forming a transparent silicone lens on the surface of the white LED coated with the white glue at the periphery; and cutting the substrate to forming a single white LED. The method avoids the phenomenon of blue light leakage of the white LED by coating the periphery of the LED chip with the white glue through the mold, the operation method is simple, low in cost and high in working efficiency, and the white light emitted by the packaged white LED is uniform and saturated in color, with no yellow or blue spot.