Middle Permian ⁸⁷Sr/⁸⁶Sr variations are recorded by the marine carbonates in the Qianfo section and the Yundadi3 well in the Sichuan Basin of the Yangtze Platform, China. Petrographic and geochemical examinations of micritic carbonates confirmed the preservation of near-primary ⁸⁷Sr/⁸⁶Sr signatures that can be utilized to construct a reliable high-resolution Sr isotope profile of the equatorial eastern Paleo-Tethys for global correlations. The high ⁸⁷Sr/⁸⁶Sr ratios associated with a eustatic regression event in the Late Capitanian (late Middle Permian) imply a predominant contribution from terrigenous materials. We observed extremely low ⁸⁷Sr/⁸⁶Sr ratios (ca. 0.7068 to 0.7069) in the 40 m-thick Capitanian interval, confirming the significant chemostratigraphic episode called the Capitanian Minimum. Globally low ⁸⁷Sr/⁸⁶Sr values in the Middle Permian were probably caused by weak continental weathering rates, suppressed riverine flux into the ocean during Pangean assembly, and increased hydrothermal flux into the ocean associated with the opening of the Neotethys during the Middle Permian. Based on the ⁸⁷Sr/⁸⁶Sr values of micritic carbonates from the Qianfo section and the Yundadi3 well, large amounts of nonradiogenic Sr may have been derived from strong submarine hydrothermal activity related to the Emeishan LIP, and areas closer to volcanic activity were more strongly affected. These combined factors were responsible for the observed low ⁸⁷Sr/⁸⁶Sr ratios in the Sichuan Basin.