Objective To establish an efficient, rapid and effective method for the simultaneous determination of seven antitumor components (evening primrose B, ferulic acid, chlorogenic acid, neochlorogenic acid, populin, protocatechuic acid, and chrysin) in the aboveground parts of Epilobium angustifolium L. by high performance liquid chromatography.The anti-tumor activities of the seven components were detected. Methods Cdc25A/B/C phosphoprotease kit, PD-1, PD-L1 kit were used for the determination of the antitumor active components in Epilobium angustifolium L. The separation was carried out on a Waters C18 column (250×4.6 mm, 5 μm) with acetonitrile-0.3% acetic acid in water as the mobile phase, at a flow rate of 1.0 mL·min-1, and the detection wavelength of 300 nm, and the column temperature was 30 ℃. Within 27 min, the seven components in Epilobium angustifolium L. were completely separated, and the sample content X and its corresponding peak area Y showed good linear relationship (R2=0.9991-0.9997).Results The method was applied to determine the seven components in willow orchids from different harvesting periods (June-November), and the results showed that the comprehensive evaluation indexes of the total contents of the seven components were highest in the leaves of Epilobium angustifolium L. in September, followed by the flowers in July, and the lowest contents in the stems in November. Conclusion The HPLC method established in this study is suitable for the quantitative analysis and quality control of Epilobium angustifolium L. The dynamic accumulation of 7 components in Willows orchid from June to November in Datong Hui Tu Autonomous County, Xining City, Qinghai Province was studied. It was found that there were significant differences of anti-tumor components in different months of Epilobium angustifolium L, which can provide a reference for determining the best harvest time of Epilobium angustifolium L artificial cultivation