Simatai Great Wall well preserves the original appearance of Ming Great Wall and some precious historical ruins. Character brick is another scenic spot of Simatai Great Wall. There is a piece of character brick on the outer wall of the city wall on the east side of White Tower, which reads "Made by Shitang Road in the Reign of Wanli". But this is only one kind of character brick of Simatai Great Wall, which is a small part of character bricks. There are many character bricks in the east and west sections of Simatai Great Wall, such as "Town Lu Cavalry Battalion in the sixth year of Wanli", "Made by Zhenwuying Right in the sixth year of Wanli" and "Made by Yansui in the sixth year of Wanli" in the west section, "Made by Shitangling Road in the sixth year of Wanli", "Made by Ningxia in the fifth year of Wanli", "Hedaying" and "Made by Shandong Left in the fifth year of Wanli" in the east section. The forms of characters are also different, including Yang text and Yin text; There are texts and countertexts; There are regular script, song script, official script and running script... Some people say that the character brick was a way to assess the quality of brick burning and trimming in Qi Jiguang during the repair period, so as to clarify responsibilities. According to historical records, only Yansui Camp and Shandong Zuoying had the task of repairing at Gubeikou (Simatai), and it was difficult to understand the names of other battalions appearing on enemy stations and side walls, because other battalions also had heavy military affairs or repairing tasks elsewhere. There is no way to verify whether there is temporary transfer of battalions or city bricks. However, character bricks are of great value for people to understand and study the Great Wall.