The geological tectonic evolution of the western Shanxi fold belt is closely related to the evolution of the North China Craton. Combining samples from Daning and Yonggu areas, the cluster isotope thermometry technique and the high- temperature solid- state rearrangement model are used to briefly discuss the sedimentary tectonic evolution of the western Shanxi fold belt.Methods: Based on the field work, carbonate rock samples from Daning and Yonggu areas were studied through microscopic observation, C—O isotope analysis, cluster isotope thermometry and high- temperature solid- state rearrangement simulation.Results: Cluster isotope thermometry and solid- state rearrangement simulation of Daning and Yonggu samples indicate that the maximum burial temperature experienced by strata of different ages in the study area is: about 60℃ for the Cambrian—Ordovician, about 45℃ for the Silurian, about 40℃ for the Devonian and Carboniferous, about 70℃ for the Permian, about 104℃ for the Triassic, about 85℃ for the Jurassic, and about 70℃ for the Cretaceous. Integrating the experimental data indicates that the pronounced absence of strata from the Late Ordovician to the Devonian in the Jinxi Flexure Belt is not the result of post- depositional erosion, but rather reflects a period during which deposition did not occur.Conclusions: Cluster- isotope analyses of the collected samples show that the matrix of the Cambrian carbonates records an average temperature of 45.8℃, whereas associated veins yield an average of 115.1℃. In the Ordovician samples, the matrix exhibits an average temperature of 36.3℃, while vein carbonates record 88.5℃. Combined with carbon–oxygen isotopic compositions and calculated fluid oxygen isotopes, the results indicate that the veins and matrix were not derived from the same fluid source, with the matrix reflecting seawater- derived diagenetic fluids.Solid- state reordering simulations demonstrate that a gradual burial- heating model cannot generate sufficient temperatures to drive Δ47 reordering, implying that higher burial temperatures are required. Considering the tectono—thermal evolution of the Jinxi Flexure Belt, elevated burial temperatures are interpreted for both the Yanshanian and Himalayan orogenic phases.The reordering results suggest that the maximum Yanshanian burial temperature (105℃) was significantly higher than temperatures reconstructed from the paleo- geothermal gradient, and this estimate is consistent with the cluster- isotope temperature of the vein carbonates from Daning (115℃). Thus, the veins within the Majiagou Formation at Daning are attributed to Yanshanian tectono—hydrothermal activity.During the Himalayan stage, persistent uplift and fold deformation occurred, and the modeled reordering temperature for this phase (85℃) closely matches the cluster- isotope temperature of the vein carbonates in the Yonggu Cambrian samples (88.47℃). This correspondence suggests that the formation of these veins was closely linked to Himalayan tectonism.