Salt lake is a kind of salinized water body, which usually refers to lakes with salinity w (NaCl eq) >: 3.5% (greater than the average salinity of seawater), and also includes dry salt lakes (underground salt lakes) with dry surface brine and composed of salt sediments and intercrystalline brine. There are about 200 kinds of salt minerals deposited in salt lakes. Humans have exploited a large number of important raw materials such as salt, alkali, mirabilite, potassium, lithium, magnesium, boron, bromine, mirabilite, gypsum, medical sludge and so on from the salt lake, such as basic chemical industry, agriculture, light industry, metallurgy, construction, medical treatment and so on.

There are also rubidium, cesium, tungsten, strontium, uranium, calcium chloride, magnesite, zeolite, hectorite and other resources with industrial significance in the salt lake. There are also a large number of special biological resources with important economic value and scientific significance, such as halophilic algae, Artemia, Spirulina, rotifer, etc., as well as drought-tolerant and saline-alkali-tolerant genetic resources, which have opened up a good prospect for human beings to obtain egg quality, natural edible pigments, energy, various industrial scientific materials and purify the environment, and turn salt lakes into "fertile soil". At the same time, salt lake is an important tourism resource and medical sludge resource. The thermal storage characteristics of salt lake brine have been used in "solar salt pond" to generate electricity.

Salt Lake is also a natural environment information and natural laboratory; Salt Lake is also a "carbon sink" and a "natural habitat". Salt lake deposits occupy a considerable area of the earth's land surface, and there are a lot of carbonate deposits, which can delay the greenhouse effect related to human beings to some extent.