The invention relates to processing technology of an aluminum pattern block for a tire mold. The processing technology comprises finish casting, rough turning, valving, upper and lower side finish milling, valving surface finish milling, finish turning and pattern modifying. The mold cavity of a casting part is taken as the overall dimension of a reference processing pattern block and the overalldimension is taken as the inner surface of a finish reference processing mold cavity, so that the gradient of the casting part is minimized, the pattern modifying workload of a bench worker is lowered greatly and the change of a pattern geometry is reduced. Moreover, damage to the finish casting inner surface is reduced while the pattern modifying workload is lowered and the formation of a shrinkage cavity under the shell of the casting part is avoided, so that the processing quality of the pattern block is enhanced and production efficiency is improved; and the technical problems of high casting gradient and pattern modifying workload instability which are not solved by technical personnel in the field are solved.