佢做官做到中郎將。漢明帝為咗提倡佛教，派咗蔡愔、秦景、王遵等十八人去印度。蔡愔一班人去到大月氏（依家嘅阿富汗），喺中天竺遇見迦葉摩騰同竺法蘭。永平十年（67年）蔡愔同攝摩騰、竺法蘭返去洛陽，明帝起咗白馬寺，比攝摩騰同竺蘭一齊譯咗本《四十二章經》。
He is an official and a general. In order to promote Buddhism, Emperor Ming of Han sent eighteen people, including Cai Yun, Qin Jing, and Wang Zun, to India. Cai Yun and his group went to the Great Moon Clan (now Afghanistan) and met Kaye Morteng and Zhu Falan in Zhongtianzhu. In the tenth year of Yongping (67 years), Cai Yun and Mo Teng and Zhu Falan went back to Luoyang, and Emperor Ming set up the White Horse Temple, and translated the "Forty-two Chapters of the Sutra" together with Mo Teng and Zhu Lan.