Abstract: The suitability of water quality is the premise of irrigation of farmland drainage resources. In order to find out the possibility and mode of irrigation of farmland drainage resources in Hetao irrigation area, we took farmland drainage of test base in Chengguan Town as the research object. The suitability of water quality was evaluated by fuzzy mathematics, and the results were verified by methods of salinity, alkalinity and salinity, comprehensive hazard coefficient and irrigation coefficient. The results showed that the drainage quality of farmland in summer irrigation period was suitable for irrigation, but it was necessary to take some measures to prevent soil salinization.