The Shiyu No.2 shipwreck site is located atop coral reefs on the east side of Shiyu in the Xisha Islands, and represents a significant underwater cultural relic within the waters of the Xisha Islands. The site has yielded a variety of porcelain wares including blue and white porcelain, egg-white glazed, white glazed, grayish-green glazed and brownish glazed ones, making it a pivotal window into the exploration of the ancient Maritime Silk Road and the export porcelain trade. Although previous researchers established the relative chronology of the site through typological analysis of blue and white porcelains, the absence of the ship’s structural remains precluded radiocarbon dating. Instead, the thermoluminescence dating method provides an alternative method to determine the absolute chronology of the site. To investigate the thermoluminescence properties and chronology of blue and white porcelains from the site, we conducted tests on 16 porcelain shards using the pre-dose saturation exponential method. The contents of radioactive elements U, Th and ⁴⁰K in the samples were analyzed using inductively coupled plasma-mass spectrometry (ICP-MS) and inductively coupled plasma-optical emission spectrometry (ICP-OES). During the dose rate calculation, key parameters including the sample’s latitude and longitude, burial depth, moisture content and contents of radioactive elements were considered. The TESCAN integrated mineral analyzer (TIMA) was utilized for the first time to determine the distribution of quartz grain sizes in the porcelain body, thereby enhancing the accuracy of the dose rate estimation. The thermoluminescence dating results indicate that this batch of blue and white porcelains was fired in a period dating from the Yuan Dynasty to the early Ming Dynasty. Within the limited error range of thermoluminescence, this is consistent with the conclusion drawn from traditional appraisal methods that the site belongs to the Yuan Dynasty. This contributes to revealing the manufacturing techniques, practical uses and possible origins of these artifacts from that historical period. Furthermore, it provides important research clues for understanding the communication routes, trade scale and cultural impact of the blue and white porcelain in maritime trade during this era.