The fly ash, discharged up to 300 million t each year, is one of the largest industrial waste residues in China. The accumulation of large quantities of fly ash will cause serious problems in nature and ecological environment. So it's significant to comprehensively utilize fly ash. A new technology is proposed in this paper. The fly ash is leached with alkali solution at the atmospheric pressure to produce white carbon black, and then alumina is recovered by sodalime sinter process. The technology can realize the utilization of fly ash economically and comprehensively. Research results indicate that the extraction of silica in fly ash is up to 72.5 % and the total extraction of alumina is less than 1.2 % when the fly ash is leached with alkali solution at the atmospheric pressure(＜125 ℃）for 45 min. White carbon black with silica content of more than 99 % can be achieved from the sodium silicate solution by the carbonation process. During the production process of the white carbon black, the conversion rate of silica in the solution reaches 98 %. The residue after leaching silica, with alumina and silica content of up to 55 % and less than 20 % respectively and mass ratio of alumina to silica of about 2.7, is suitable for recovering alumina by sodalime sinter process. The optimum conditions of sodalime sinter process are as follows: molar ratio of sodium oxide to alumina being 0.95~1.0, molar ratio of calcium oxide to silica being 1.8~2.0, roasting temperature being 1 200~1 250 ℃, leaching temperature being 75~85 ℃ and leaching time being 10~20 min. Under the above optimum conditions, the recovery of alumina is more than 86 %. It has remarkable economic and social benefits in comprehensive utilization of fly ash to produce white carbon black and alumina.