Rapid fouling tests were used to investigate the scale-preventing property of ZX type scale inhibitors in evaporation of salt electrolyte. ZX type scale inhibitors were tested at high temperature under the boiling conditions. The results indicate that ZX type scale inhibitors have remarkable scale preventing performance during evaporation of salt electrolyte even at the temperature up to 150 degreesC. Among them, ZX III type scale inhibitor is the best with the rate of scale-preventing reaching to 88.9%. In addition, the scale preventing mechanism of ZX type scale inhibitors was analyzed and its application prospect in the field of continuous commercial fouling preventing discussed.