Lithium resource recovery type salt lake brine comprehensive utilization method

The invention relates to the technical field of efficient comprehensive utilization of salt lake resources, and particularly discloses a comprehensive utilization method of lithium resource recovery type salt lake brine, which comprises the following steps: adding magnesium oxide into high-level old brine, stirring, filtering, carrying out pretreatment, adding filtrate into a membrane separation system, adjusting the pH value, preparing borax, and collecting magnesium oxide filter cakes for adsorbing impurities; doping the magnesium oxide filter cake into another old brine, adding hydrochloric acid to adjust the pH value, filtering, and extracting crude boric acid; producing refined boric acid from the coarse boric acid, and evaporating and concentrating filtrate in a salt pan; after high-lithium old brine enriched in a salt pan is calcined, tail gas is absorbed to obtain hydrochloric acid, a calcined product is leached and filtered to obtain magnesium oxide, and lithium carbonate is produced from leached fil