In order to better preserve cultural relics in the environment of the northwest region where the seasons are distinct and climate changes are sometimes drastic, we investigated the architectural design, ventilation, presence of aerosols and conservation environment of Pit No.1 in the open Emperor Qin’s Terracotta Museum, and then compared these factors with those of the enclosed Han Yangling Museum. It was found that the completely enclosed building of Han Yangling Mausoleum has relatively constant temperature and humidity, and the obvious advantage of blocking outdoor pollutants; however, it still does not entirely stop the seasonal fluctuations of temperature and humidity as well as infiltration of outdoor air pollutants. Furthermore, the occurrence of indoor pollution, moisture condensation inside glass enclosures and the appearance of alkali on large areas of cultural relics have to be prevented as well. Therefore, suitable ways still need to be explored to preserve cultural relics of site areas, not only maintaining the relative stability of temperature and humidity, and cleanliness of the preservation environment of the cultural relics, but also alleviating the common issues of enclosed buildings mentioned above, so as to prolong as much as possible the life of ruins and cultural relics, and to meet the demands of visitors.