During his tenure, he monopolized the power, abused power for personal gain, and imposed exorbitant taxes and miscellaneous fees, and his administration was even more demanding. In 208 BC, Li Si was designed and killed, and later became the prime minister of Qin State. In the third year, he forced Qin Ershi to commit suicide and made Zi Ying king of Qin. Soon, he was killed by Zi Ying's design, killing three tribes.
Zhao Gao started as a eunuch, and with the favor of Qin Ershi and Hu Hai, he pushed the tyrannical politics of the Qin Dynasty to the peak, thus accelerating its demise. Therefore, Lu Jia lamented that "Qin criminal law remained unchanged and Zhao was killed" (referring to the demise of the Qin Dynasty); Liu Xiang, editor-in-chief of the Warring States Policy, even bluntly said: "It is not easy to have the same surname as Wang, and the country has died. Therefore, the king's rule of the world lies in his deeds, not in his belief in the same surname. "
In addition, Zhao Gao was also a master of calligraphy in Qin and Han Dynasties. Xu Shen's Preface to Explaining Words in the Eastern Han Dynasty said: "Zhao Gao made the almanac, and adopted the seal script of Shihua or made some provincial changes." The Book of Ancient and Modern Characters in the North of Qing Dynasty contains 59 calligraphers in Qin, Han and Wu Dynasties, including Zhao Gao. In the Southern Song Dynasty, Yang Xin called Zhao Gao "Da Zhuan" in the Book Collection. Zhang Tang's Broken Book, Volume One of the Great Seal Characters, said: "Zhao Gao is good at seal cutting. Teach Hu Hai, the youngest son of the emperor. " The author of his six articles is Hou.