After long-term monitoring of the microenvironment at the Tanjiapo Site Museum of the Tongguan kiln Site, we compared and analyzed the data on air temperature, relative humidity, soil temperature and soil moisture content to evaluate their patterns of variation and characteristics in order to get a preliminary understanding of the environmental conditions at this historical site. The results indicate that the damp and rainy weather conditions caused high temperatures and high humidity inside the Tanjiapo Site Museum of the Tongguan Kiln Site and its earthen site. The site was prone to suffering greatly from erosion due to underground water, which resulted in direct or indirect diseases and accelerated physical and biological damage to the earthen site. We proposed to control the site environment scientifically and properly, to set up an environmental database and to form a set of integrated forecast and alarm systems.