This data set is the hydrogen isotope data of leaf wax from 10 m core of Qinghai Lake in Tengchong, Southeast of Qinghai Tibet Plateau. Tengchong Qinghai Lake is a small crater lake in Gaoligong Mountain, Southwest China. Core samples were collected at about 4m in the center of the lake in 2017. Ams-14c dating was used to establish the age series. The n-alkane leaf wax hydrogen isotope was determined and analyzed by Agilent 6890 GC gas chromatograph and Deltaplus XL type chromatography isotope mass spectrometry. The data reflect the information of atmospheric precipitation isotope in this area, and play an important role in the study of monsoon precipitation changes in southwest monsoon region in the past 40000 years. Data acquisition, pre-processing extraction and instrument testing were completed in strict accordance with the relevant operating procedures.