The invention discloses an energy-saving and environmentally-friendly salt lake brine lithium extracting technology. The technology comprises the steps of atomizing and forcibly evaporating high-salinity brine through a tower type reinforcing atomizing circulating concentrating and salt separating device, thus realizing high-multiple concentration and salt reducing and lithium enriching of the brine; processing the concentrated lithium-enriched brine by multi-stage high-pressure nanofiltration to realize salt separating and magnesium removing; retuning the primary nanofiltration low-lithium concentrated water to a tower type concentrating liquid inlet part; extracting lithium from the lithium-enriched nanofiltration water in a liquid-liquid extraction manner; returning lithium-containing raffinate water phase and extracting agent regenerating washing liquid to a nanofiltration liquid inlet part, and further recovering lithium; evaporating high-lithium reverse extraction liquid, and recovering acid for regenerating an extraction additive; evaporating to remove acid to obtain solid high-lithium compound salt; performing solid-liquid extraction through ethyl alcohol; volatilizing theobtained lithium chloride ethyl alcohol extracting solution; and recovering ethyl alcohol to obtain high-purity lithium chloride. The technology is obvious in energy saving effect in the whole process, high in lithium recovery rate, low in production cost, safe, environmentally friendly, and applicable to extraction and production of lithium in various types of high-salinity and high-magnesium-lithium-ratio salt lake brine.