Kadsura heteroclita (Roxb) Craib stem (KHS) is a medicinal plant used for the treatment of rheumatism arthritis diseases in Tujia ethnomedicine. Thus far, the complex chemical compositions in KHS are not clear, and the levels of the major compounds in KHS are not well understood. In this study, a novel UHPLC-Q-Orbitrap HRMS method was established for the simultaneous quali-quantitative analysis of KHS. A total of 204 compounds were identified, including triterpenoids, lignans, sesquiterpenes, fatty acids, phenolic acids, and flavonoids, more than 100 of which were first discovered in KHS. Using the same method, 12 representative bioactive components were successfully quantified. The method was fully validated by linearity, LOD, LOQ, precision, stability, recovery, and matrix effects, and it was applied to quantify the 12 representative compounds in 4 batches of KHS. As this method enables retrospective data analysis and has no upper limit to the number of analytes in a single run, it can be applied to quantify more active components of KHS in the future.