The invention discloses a technology for extracting lithium from lithium-containing alkaline brine based on mixer settlers. The technology includes the following steps that an extraction water phase is provided; an extraction organic phase is provided; extraction is conducted; washing is conducted; back extraction is conducted; and regeneration is conducted. According to the technology, a brand new extraction system is adopted, the lithium is extracted from a lithium-containing alkaline brine system, in addition, an extraction-washing-back extraction-regeneration total-process technology basedon the mixer settlers is determined for the first time, people not only rest on the fundamental research of an extraction section, finally, technological parameters matched with the extraction systemare determined, and an industrial production technological path based on the mixer settlers is provided, wherein the technological parameters include the stage number of each section, the flow ratioand the concentration of all reagents. The technology for extracting the lithium from the lithium-containing alkaline brine is particularly suitable for a filter liquid system generated in the processthat a lithium chloride solution is used for preparing a lithium carbonate product, so that the lithium is further extracted from the filter liquid system, true comprehensive recycling of salt lake brine is achieved, and the practical significance is achieved.