The traditional precipitation method for extracting lithium has a long production cycle, which is not suitable for brine with low lithium concentration. Therefore, the output of extracting lithium from salt lake grows slowly, which is difficult to meet the needs of new energy industry. Therefore, it is an urgent need for the lithium industry to develop new technology for extracting lithium from brine with high magnesium lithium ratio. This paper summarizes the development of new lithium extraction processes such as adsorption, solvent extraction, membrane and electrochemical methods. It is found that aluminum based adsorbents have been used in industrial production, but its adsorption capacity is significantly smaller than that of manganese and titanium based adsorbents, and the dissolution loss and long adsorption equilibrium time of the latter two are the key factors restricting their industrialization. Neutral phosphorus extractant have attracted the most attention, but it is easy to corrode and appear the third phase. Corrosion free amide extraction system has been used to industrially extract lithium from chloride type brine, but its stability needs long-term attention. Moreover, solvent extraction process has a long process flow and high acid and alkali consumption. The membrane method cannot remove magnesium deeply, so it needs to be combined with other methods to extract lithium, which consumes a large amount of water resources. Electrodialysis and "rocking chair" electrochemistry realize continuous lithium extraction, accelerate the adsorption rate, and avoid the use of eluent. The reduction of power consumption with the optimization of lithium extraction system and working conditions, electrochemical lithium extraction technology will usher in a broad industrial prospect. The resource consumption and environmental impact of the above new process for extracting lithium from brine are less than that of the traditional precipitation method, which has significant competitive advantages for salt lakes with high magnesium lithium ratio, but each has its own disadvantages. Therefore, in the future, lithium extraction from salt lake brine should strengthen the integration and coupling of a variety of new technologies, move forward the lithium extraction process, improve the lithium recovery rate of the whole process and the comprehensive utilization of various resources.