The main factors that affect the stability and reliability of catalytic sensor witch is used to detect CH4 volume fraction in mine are coking and catalytic deactivation because of the poisoning of catalyst.Al2O3 is used as the carrier of catalyst

the effect of the adulteration of Al（NO3）3 and rare-earth materials on catalytic sensor performance is studied.The results show that the adulteration of rare-earth enhances anti-coking capability of catalytic sensor;the sensor has excellent anti-poisoning ability to H2S because CeO2 surface has a large number of O2-;the sensor has excellent anti-poisoning ability to silicon because the addition of the Al（NO3）3 when is decomposed introduces a wealth of pore structure in the internal components.