The model experiment adopted brackish water of four different mineralizations for farmland irrigation.3.0 g/L brackish water can irrigate continuously.If flood season rainfall adequate and irrigation whth freshwater in winter in the region, 4.0 g/L brackish water can irrigate continuously.Mineralization more than brackish water 6.0 g/L were not suitable for farmland irrigation, must be blended freshwater with brackish water to mineralization less than 4.0 g/L.