Cultural relics are materialized civilizations. The non-renewability of cultural relics determines that the research on them should take non-destructive ways which also stand at the research frontier of cultural relic conservation in recent years. With reference to the recent progress on the application of ultrasonic technology in China and abroad in this field, the review introduces several cases of evaluating weathering degrees, detecting internal flaws, underwater detection and restoration of cultural relics by means of the ultrasonic technology. Potential influencing factors are categorized and possible solutions are discussed. The ultrasonic technology is non-destructive, fast and accurate. More and more cases show that the ultrasonic technology will be more widely applied in the field of cultural relic conservation and provide new ideas for solving problems therein.