Bricks and tiles are ceramic building materials, which have been commonly used for palaces and other high-grade buildings since the Western Zhou Dynasty. During the Qin and Han Dynasties, with unification and centralization and the massive development of civil engineering in various places, the pottery industry tended to mature. In addition, the brick chamber tomb appeared in the late Western Han Dynasty, and quickly became popular nationwide in the Eastern Han Dynasty. All the factors above made pottery products for buildings occupy an important position in the pottery industry (with the name of “Qin bricks and Han tiles”). The Han Dynasties were a period of prosperity for the pottery industry, with the pottery products more widely used than in the Qin Dynasty, and the structure of brick and tile kilns changing as their functions changed. In order to explore the scientific logic of the changes in the characteristics and structures of Han Dynasty brick and tile kilns, numerical simulation of the flow field and temperature field during firing in Han Dynasty brick and tile kilns with different structures was conducted. Han Dynasty brick and tile kilns were semi-inverted-flame ones, with the advantages of rapid heating, long holding times and even temperature distribution compared to the earlier horizontal cavity kilns and rising-flame kilns. Through the analyses of archaeological reports and numerical simulations, the functional and structural relationships of Han Dynasty brick and tile kilns were studied. Firstly, based on the previous typological studies of Han Dynasty brick and tile kilns, the kilns were divided into single-flue and multiple-flue ones according to the pattern of change in the structure of each part of the kiln during the Han Dynasties. Then, based on excavations of kiln sites and documentation of the ancient kiln industry, the construction, yarding and firing methods of Han Dynasty brick and tile kilns were summarized. Finally, simulations were modeled based on the above research with the aim of investigating the influence of variation in the number of flues on firing in the brick and tile kilns. Furthermore, considering such factors as the unearthed relics, age and preservation in the kiln, Han Dynasty Kiln site Y6 at Sulin Village, Jiaozuo, Henan Province and Kiln No.11 at the Capital City site of the Eastern Zhou Dynasty in Luoyang were selected to carry out numerical simulations respectively. Han bricks were taken as examples of kiln products, the computational fluid software FLUENT was mainly used to simulate the flow field and temperature field in the kiln, and the flow of flue gas in the Han Dynasty kiln was analyzed from the perspective of fluid mechanics and thermodynamics. The results indicate:1) Han Dynasty brick and tile kilns were built in a semi-cavernous manner, with the walls rammed and coated with grass-mixed mud after excavation to create a flat shape. The roof of the kiln in the Western Han period was capped with a four-sided knotted dome or vault roof, while in the Eastern Han period the roof was capped with a four-cornered vault dome or vault roof. A side-standing arrangement of billets was adopted for yarding in the kiln; the firing temperature of the kiln was around 1 000 ℃. 2) The structural changes of brick and tile kilns in the Han Dynasties adapted to the expanding demand for ceramic building materials in society at that time and were scientifically reasonable. In addition, the flue gas flow characteristics of the semi-inverted-flame kiln were verified through simulation experiments, especially the structural change of the flue from one to many making the temperature distribution in the kiln more uniform to raise the firing temperature and improve the quality of bricks and tiles. 3) After preliminary research, it was found that, in Han Dynasty brick and tile kilns, a fire wall was set up between the firing chamber and the kiln chamber, which played a role in insulation and slowing down the flow rate of high-temperature flue gas. This structure was of great significance for firing large numbers of high-quality artifacts such as pottery figurines. According to this research, the structural changes in Han Dynasty brick and tile kilns are somewhat rational, with multiple-flue kilns having the advantage of being more insulated than single-flue ones, improving temperature distribution and insulation within the kiln chamber, increasing the firing temperature range and firing quality of products. This explains the logic of structural changes in Han Dynasty brick and tile kilns, namely that it corresponded to the needs caused by the rise of brick chamber tombs and large buildings during the mid- to late-Western Han period. These changes laid a technical foundation for the subsequent large-scale firing of ceramics with higher firing temperature conditions. The results demonstrate the feasibility of numerical simulations in kiln research and provide a scientific basis for further exploration of the production levels of Han Dynasty kilns.