Based on the soil column breakthrough experiment in laboratory, four treatments (desulfurization gypsum with none or one or three leaching times; no desulfurization gypsun with none leaching time) were set up. With the analysis of relationship among these three ions: NH+4, Ca2+, Na+ and the hydraulic conductivity (HC), the effects of the leaching times and flue gas desulfurization gypsum on ammonium nitrogen transport in solonetz were investigated. The results showed that the suppression of the adsorption of ammonium was occurred in the solonetz combined with desulfurization gypsum without leaching. But with the leaching times increasing before penetration, the slope of the breakthrough curve reduced and the adsorption enhanced. In the view of controlling water and salt, promoting the adsorption of fertilizer, inhibition of soil secondary salinization, it was inappropriate to put the ammonium fertilizer together with desulfurization gypsum in solonetz at the same time. It suggested that the solonetz mixed with desulfurization gypsum should be leached two times, which are autumn irrigation and spring irrigation, with the leaching amount of 662.7m3/hm2. On the basis of ensuring the reclamation effect, this leaching way can decrease the amount of autumn irrigation and distribute the limited freshwater resources reasonably in the area.