Industrial water-saving comprehensive evaluation is related to the aspects such as society, economy and environment, is a special and complex process. Combining the theory of matter element analysis with extension theory, the paper established extension matter element evaluation model of industrial water-saving. In the case of Xi''an, it comprehensively evaluated the situation of industrial water-saving in these areas according to the evaluation model. The results show that the method has reasonable structure and directly clear reflects industrial water-saving comprehensive level of Erdos City, then according to the evaluation results the paper put forward reasonable water-saving measures so as to improve industrial water saving level. It has application value for engineering projects.