Seawater desalination method

The invention discloses a seawater desalination method. The seawater desalination method comprises the following steps: seawater pretreatment, ultrafiltration filtration, first-stage reverse osmosis membrane filtration, second-stage reverse osmosis membrane filtration and mineralization. The mineralization comprises the steps of introducing carbon dioxide gas into water of a desalination water tank, and adding a saturated limewater solution, wherein the adding proportion of carbon dioxide and saturated limewater is 2.5 to 1, and the contents of residual chlorine at a raw seawater inlet pipeline, a front filter, an ultrafiltration system, an ultrafiltration water producing pipeline and an ultrafiltration water tank are respectively 5ppm, 4ppm, 2ppm, 1ppm and 0.8ppm. The mineralization method is direct, simple, efficient, short in consumed time and stable in water quality; and a sodium hypochlorite adding site is arranged at a seawater extraction hole, and a reducing agent adding site and a non-oxidation steril