Abstract: A purification method and system for a lithium-extraction dissolving-solution of an aluminum electrolysis waste, the method includes: adding an alkaline mixture to the lithium-extraction dissolving-solution until a pH of the lithium-extraction dissolving-solution reaches a first target pH, and filtering the lithium-extraction dissolving-solution to obtain a first filtrate after performing a first reaction in the lithium-extraction dissolving-solution; the first target pH is 11.5˜12; and adding a decalcification agent and a catalyst to the first filtrate until a pH of the first filtrate reaches a second target pH, and filtering the first filtrate to obtain a purified dissolving-solution after performing a second reaction in the first filtrate, the second target pH being 11.5˜12.