AbstractSacha inchi oil with large amount of double bonds (DBs) in allylic positions and double‐allylic positions was converted to an epoxidized oil by using H2O2 as the reactant. The success of this modification process has been demonstrated by Fourier transform infrared spectroscopy and 1H‐NMR spectra. The influence of the reaction agent, the components in the catalyst system such as Na2WO4, PTC (benzyldimethylstearylammonium chloride hydrate), H3PO4, and temperature on the epoxidation reaction has been studied systematically. Through the evaluation of oxirane oxygen of the epoxidized oil, the conversion of DBs, and the selectivity of the catalyst, the optimum conditions are found. They are as DB/H2O2/Na2WO4 molar ratio of 1/1.5/0.0075 and Na2WO4/PTC/H3PO4 molar ratio of 1/0.45/2. The reaction time was shortened to only 8 min when the epoxidation reaction was performed at 60°C. The epoxidized sacha inchi oil had the oxirane oxygen reaching 8.78% with a yield of 82.12% and a catalytic selectivity of 0.85.