Based on the story of an archaeologist who investigated the hanging coffin in the Three Gorges, this paper introduces the basic principles, common detection methods and applications of radiocarbon dating, and systematically popularizing the relevant knowledge of 14 C dating.The methods of classification, sampling and analysis of radiocarbon samples are introduced.At the same time, this paper introduces the cliff tomb in Sichuan-Chongqing area, showing readers the unique charm of ancient Bashu culture.