Shi Huangdi, the first emperor of China, is known for his construction of the Great Wall of China, not tearing down the walls of Chinese kingdoms. The Great Wall was built to protect the northern border of China from invasions by nomadic tribes such as the Xiongnu. However, if you are referring to the possibility of Shi Huangdi tearing down existing city walls during his unification of China, there is no historical evidence to support such an action. He instead focused on strengthening and expanding the walls to protect his empire.
