Abstract: Aiming at the requirements of daily safety management and control of tailings pond， using set pair analysis method and extension theory， a tailings pond safety situation and sensitive factor analysis model based on set pair extension side distance correlation algorithm is proposed.The concept of similarity， difference and opposition in set pair analysis and the description method of matter element in extension theory are used to establish the analysis system for describing the safety situation of tailings pond. Considering that the safety evaluation index of tailings pond has the characteristics of "extremely large" or "extremely small"， the set pair extension side distance correlation algorithm is established based on the principle of the optimal value of the end point of the safety level interval. The similar， different and opposite parameters of the safety state of tailings pond are calculated， and the comprehensive safety connection degree of tailings pond and the safety impact connection degree of the index are determined. Based on the definition of set pair situation， an analysis model of the safety situation of tailings pond and its sensitive factors was constructed. By calculating the set pair situation of tailings pond and analyzing the similar， different and opposite parameters， the change trend of the overall safety state of tailings pond has been reflected well and the influence degree of various evaluation indexes on the safety status of tailings pond has been systematically analyzed so as to provide a working path for formulating effective safety prevention and control measures.A tailings pond safety situation and its sensitive factor analysis model based on set pair extension side distance correlation algorithm is used to analyze the safety status and change trend of a tailings pond. The analysis results show that the overall safety state of the tailings pond is N2， and its set pair situation is 0.57， which reflects that the tailings pond is in a good condition， but its safety state has a strong trend of developing to the unsafe level. At the same time， the first level sensitive indexes affecting the safety state of the tailings pond are determined as the downstream slope ratio （C22）， bulk density （C32） and geological condition （C41）， and the control degree from large to small is C22，C32 and C41， which is basically consistent with the actual situation of the tailing pond.

Key words: tailings pond, safety situation, sensitive factors, set pair analysis, extension side distance correlation function