Preparation method of pepper oleoresin

The invention relates to a preparation method of pepper oleoresin. According to the invention, flavor substances in pepper are quickly extracted through unique room temperature-program boosting in combination of an ultrasonic-microwave synergistic extraction method based on a field effect-accelerated solvent method, wherein the pressure range is 6-8 bars, the boosting extraction time is 10-30 minutes, the ultrasonic power is 50W, the frequency is 40KHz, the microwave power is 70-500W, the microwave frequency is 2450MHz, and the synergistic extraction time is 10-20 minutes; and the extracted flavor substances are subjected to filtering, solvent removing, drying and like processes to prepare the pepper oleoresin. The extraction method disclosed by the invention is safe and efficient, and has the advantages of short extracting time, high pepper oleoresin yield, higher piperine content, sufficient peppery taste and stronger fragrance compared with extraction methods such as ultrasonic extraction, microwave extraction, solvent extraction, Soxhlet extraction, hot reflux and the like.