Abstract: [Objective] To prepare Glycyrrhiza flavonoids nano emulsion by drawing the pseudo ternary phase diagram optimization prescription and to evaluate its stability. [Methods] The EL-40 and Span-80, isopropyl myristate（IPM）, and glycerol were used as surfactant, oil phase, and cosurfactant respectively. They were mixed to prepare Glycyrrhiza flavonoids nano emulsion. The accelerated test in the conditions of high temperature, high humidity and constant temperature was conducted respectively to evaluate the stability of the Glycyrrhiza flavonoids nano emulsion. [Results] The determined prescription was as following： 0.2 g of Glycyrrhiza flavonoids, 1.2 g of EL-40, 0.3 g of Span-80, 0.5 g of glycerol, 0.5 g IPM, and 4.0 g distilled water.The prepared Glycyrrhiza flavonoids nano emulsion was clear and transparent without layer, and it was evaluated as stable in accelerated test. [Conclusion] The developed technology in this study for preparation of Glycyrrhiza flavonoids nano emulsion is simple to operate and the nano emulsion exhibits good stability.