The invention discloses an elemene micro-emulsion, which is prepared from raw material components fed in a certain proportion. The raw material components include elemene, surfactant, cosurfactant and water or buffer solution with a pH between 5 and 8, wherein the surfactant is one or any mixture of tween, polyoxyethylene castor oil and polyglycol stearate; the cosurfactant is one or any mixture of ethanol, 1,3-propanediol and glycerin; the pH of the elemene micro-emulsion is in a range between 5 and 8; the concentration of elemene in the elemene micro-emulsion is 1 to 5 g / 100 ml; the feed ratio in part by mass of elemene to surfactant to cosurfactant is 1-5:1-40:1-10; and the unit of mass part / volume part is g / ml. The elemene micro-emulsion has the advantages of improving elemene bioavailability, ensuring steadier blood concentration, reducing toxic side effect compared with the prior preparation, indirectly improving the efficacy of elemene serving as a chemotherapeutic medicament and enhancing the anti-tumor effect of elemene.