Abstract: According to researches of detection and evaluation techniques on corrosion state of atmospheric vertical storage tank, integrity test method and the significance of safety assessment on them were introduced combined with analysis of relevant literatures. Moreover, the rationality and limitations of acoustic emission on line testing and magnetic flux leakage off line detection were discussed. After the comparative analysis on classification of tested tank floors, the result showed that the conclusions of two methods were basically consistent. All of these proved that acoustic emission testing on line and evaluation were valuable in petroleum and petrochemical industry, and this technique had a wide prospection.