He hailed from Guangling 廣陵 (near modern Baoying 寶應, Jiangsu) and was with the age of 15 sui appointed apprentice court gentleman (tongzi lang 童子郎), as which he had the opportunity to enroll at the National University (taixue 太學). Successful in his studies, he was given the status of filial and incorrupt appointeee (xiaolian 孝廉) and was appointed mayor (zhang 長) of Jiqiu 即丘. During the reign of Emperor Ling 漢靈帝 (r. 167-189) Zang Hong withdrew from office and returned to his home town for a while. Yet when Dong Zhuo 董卓 usurped the power of the Han central government, Zang Hong became a supporter of Zhang Chao 張超, governor (taishou 太守) of the commandery of Guangling 廣陵, who fought against the warlord Cao Cao 曹操.
He instigated several regional governors to rebel against Dong Zhuo: Liu Dai 劉岱, regional inspector (cishi 刺史) of the province of Yanzhou 兖州, Kong Bai 孔伯, regional inspector of Yuzhou 豫州, and Zhang Miao 張邈, governor of Chenliu 陳留. The rebels erected an altar under a group of sour date trees (suanzao 酸棗) and swore brotherhood in their fight against the usurper. The group offered their support to Yuan Shao, and Zang Hong as their leader was by Yuan Shao appointed regional inspector of Qingzhou 青州 and later governor of Dongjun 東郡. At that time Cao Cao besieged Zhang Chao in the city of Yongqiu 雍丘. Zang Hong asked Yuan Shao to be sent for relief, but the potentate declined. In the consequence Yongqiu fell into the hands of Cao Cao who extirpated Zhang Chao's family. Zong Hong therefore broke with Yuan Shao, who thereupon sent a contingent to besiege Dongjun. The defenders were able to resist more than a year, and Zang Hong refused to surrended. In the end the city was assailed and Zang Hong died during the fights.
Zang Hong was famous for his excellent literary style. Liu Xidai 劉熙載 praised him as one of the two most excellent writers of the last decades of the Han (besides Kong Wenju 孔文舉, i.e. Kong Rong 孔融), and even said that he was a better writer than Cao Zhi 曹植 (Cao Zijian 曹子建) and Chen Lin 陳琳 (Chen Kongzhang 陳孔璋). Of Zang Hong's writitings two texts survive, namely the Suanzao mengci 酸棗盟辭 "The oath of the Sour Dates" and the letter Da Chen Lin shu 答陳琳書 that are both quoted in his official biography in the history book Sanguozhi 三國志.