A submicro emulsion of paclitaxel, the preparation method and the use thereof are disclosed. Said submicro emulsion comprises a paclitaxel-steroid complex, oil for injection, water for injection, an emulsifier, a co-emulsifier and a isotonizing agent, wherein the mole ratio of paclitaxel to steroid in the complex is 1: 0.2-4, preferably 1: 0.25-2. Said submicro emulsion is useful for the treatment of malignant tumor. The particle size of the emulsion is less than 400 nm and the pH value is 3.5-6.