Chang’an City (known as Xi’an now) was the capital of China during the Tang Dynasty, and its city wall is an important part of China’s ancient city heritage. The city wall was built from rammed earth. The construction above the ground is difficult to preserve, with only the basic framework remaining. Since the site is highly overlapped with the core area of modern Xi’an, some buried city walls and gate sites have been unexpectedly discovered with the development of urban construction. Those sites occupy a certain amount of urban space and are not recognizable, therefore, how to protect and display these city wall sites and integrate them with the contemporary city has become a problem. In this paper, the characteristics of the existing methods of displaying city wall sites are analyzed first, such as parks based at city wall sites, greening signs, city wall installation art displays, and city wall museums. Secondly, the paper discusses how to ensure the authenticity of the site under the condition that only the basic framework remains to make the information of the site understood by the public and to make the site memorable historical imagery of the city through different methods of display. Finally, the paper explores the applicability of the different methods of displaying the sites in different modern urban environments, to facilitate the adaptive reuse of the sites under the premise of proper protection, so that the ancient sites can be integrated better into contemporary urban life and thus serve the public.