Nanofiltration system and system and method for treating high-concentration brine

The invention discloses a nanofiltration system which comprises a wastewater storage pool and further comprises a primary nanofiltration unit, the primary nanofiltration unit comprises a primary nanofiltration first section, a primary nanofiltration second section, a primary nanofiltration third section, a primary nanofiltration nth section, a primary nanofiltration (n + 1) th section, a primary nanofiltration (n + 2) th section and a primary nanofiltration (n + 3) th section which are sequentially connected, an inter-section booster pump is also arranged on a pipeline between the concentrated water outlet of the first-stage nanofiltration second section and the first-stage nanofiltration third section; the concentrated water outlet of the nth section of the first-stage nanofiltration is connected with the water inlet of the (n + 1) th section of the first-stage nanofiltration after sequentially passing through a flow meter in front of the first-stage nanofiltration booster pump, a pressure transmitter in fro