In order to explore the overall climate characteristics of Kunming Basin since Quaternary and the evolution of Dianchi Lake. Based on environmental magnetism, TOC, pH and other indicators, this paper systematically studied the core sediments of DC1 borehole on the eastern bank of Dianchi Lake, and tested the mass susceptibility (χ), non-magnetic hysteresis remanence (ARM), saturated isothermal remanence (SIRM), low-frequency susceptibility ( χlf ), high-frequency susceptibility ( χhf ), soft remanence (IRM-300 mT), pH value and total organic carbon (TOC). The results show that the magnetic characteristics of DC1 sediments are dominated by ferrous magnetic minerals, and the content of antiferromagnetic hematite is relatively high in the 0.3-3.6 m and 14.7-15.6 m sections. Combined with the formation environment of hematite, it reflects that the sedimentary environment of these two sections is lake retreat period. In addition, combined with the relationship between TOC and magnetic susceptibility at different depths, it is shown that the high value of TOC is related to the dissolution of magnetic minerals in fine particles. Combined with the content characteristics of TOC in each section, it shows that the climate type corresponding to the whole 21 m deposition process is mainly warm climate.