Seawater contains a lot of salts and many elements, many of which are needed by human body. However, the concentration of various substances in seawater is too high, far exceeding the hygienic standard of drinking water. If consumed in large quantities, it will lead to excessive entry of certain elements into the human body, affecting the normal physiological functions of the human body, and causing dehydration of the human body.

More than 70% of the earth's surface is covered by water, and the rest of the land, which accounts for about 30% of the earth's surface, also has water. The fresh water reserve is 3.5% × 10.8 billion m3, accounting for 2.53% of the total reserves. Due to development difficulties or technical and economic constraints, so far, seawater, deep groundwater, ice and snow solid fresh water are rarely used directly. Lakes, rivers and shallow underground fresh water resources, which are relatively easy to develop and utilize and have the closest relationship with human life and production, only account for 0.34% of the total fresh water reserves, accounting for 104.6% × 10.4 billion m3, less than one ten thousandth of the total global water reserves, and this part of the water distribution is extremely uneven. With the development of economy and the increase of population, the world water consumption is increasing year by year. Using seawater desalination technology to get water from the sea is the future development trend, and reverse osmosis desalination is the focus of development at this stage.