The invention relates to a 
seawater desalination device and a method, and relates to the 
seawater device and its method by combining an electrolytic technology, a 
capacitance adsorption deionization technology and a low pressure 
reverse osmosis technology. The device comprises an electrolytic purifying 
system, a 
capacitance adsorption deionization 
system and a low pressure 
reverse osmosis system; the electrolytic purifying system comprises a stop valve, a 
water supply pump, an electrolytic 
machine, a deposition pot and a 
microfiltration apparatus; the 
capacitance adsorption deionization system comprises the stop valve, an 
elevator pump, a 
cartridge filter, the 
water supply pump, a capacitance adsorption deionization apparatus, a primary 
fresh water storage tank and a concentrated water 
booster pump; the low pressure 
reverse osmosis system comprises the stop valve, the 
water supply pump, the 
cartridge filter, a 
high pressure pump, a low pressure reverse 
osmosis membrane component and a 
fresh water storage tank. The method comprises the following steps: electrolyzing, performing capacitance adsorption deionization and primarily desalinating, finally performing low pressure 
reverse osmosis desalination. The method has the advantages of short process flow, small investment and less environmental 
pollution, the reverse 
osmosis system material has the advantages of low requirement and low cost, and solves the problem of nationalization, and the 
seawater desalination device has the advantages of high efficiency, low 
energy consumption, low production cost, high integrated level of the device, small volume, easy operation and the like.