The technology of clumped isotope(D47) thermometry has been applied in the study of the diagenetic environment of carbonate rock as a new experimental technique in recent years. The paper introduces the principle and application method of the clumped istope thermometry. Taking the middle-lower Cambrian dolomites in Tarim Basin as an example, 11 samples were chosen to test D47 value and carbon and oxygen isotope of dolomites, and further, to calculate the diagenetic temperature and δ18O of paleofluids. According to the comprehensive analysis, the diagenetic environment of different types of dolomites is different, and the diagenetic fluid is different too. The granular dolomite formed in low-temperature penecontemporaneous-shallow buried environment, and the diagenetic fluid is seawater. The fine-grained dolomite is formed in the deep-buried diagenetic environment, and the original rock is subjected to high-temperature recrystal ization, and the diagenetic fluid is underground thermal brine. The dolomite cements in the pores or fractures are the products of the precipitation of Mg-rich thermal brine in a deep-buried diagenetic environment. It is proved that the clumped isotope thermometry can obtain the diagenetic temperature of dolomite more effectively and reduce the multi-solution of reservoir genesis, which provides a new means and basis for the future study of reservoir genesis.