Long before Li Duozuo's time, his ancestors had submitted to Chinese rule, and the family history was not well preserved.
Empress Dowager Wu commissioned the ethnically Baekje general Heichi Changzhi, assisted by Li Duozuo, to defend against Ashina Gudulu's attack, and they were able to defeat the Eastern Tujue forces at Huanghuadui (黃花堆, in modern Shuozhou, Shanxi), causing the Eastern Tujue forces to flee.
In 702, when Wu Zetian was apparently contemplating further military action in the northeast and put the chancellor Wei Yuanzhong in command, Li Duozuo made acting commandant at You Prefecture (幽州, roughly modern Beijing), assisted by the generals Xue Na and Luo Wuzheng (駱務整).
As of spring 705, Wu Zetian was ill, and her lovers Zhang Yizhi and Zhang Changzong wielded much power, leading to speculation that they might try to displace her son Li Xian the Crown Prince, a former emperor (Emperor Ruizong's older brother).
Li Duozuo, in fear, pretended to serve the interests of Empress Wei and avoided being killed himself.
Meanwhile, however, resentment against Empress Wei and Wu Sansi was brewing, centering on Emperor Zhongzong's son Li Chongjun the Crown Prince, born of a concubine.
Li Duozuo's son-in-law Ye Huli (野呼利) also participated and served as the forward commander of the coup forces.
Meanwhile, however, Emperor Zhongzong's eunuch Yang Sixu (楊思勗) counterattacked, killing Ye and discouraging the coup forces.
Li Duozuo was posthumously restored to the title of Prince of Liaoyang, and his family members were released.