A submicron emulsion of paclitaxel, the preparation method and the use thereof are disclosed. Said paclitaxel submicron emulsion comprises paclitarxel/steroid complex, oil for injection, water for injection, emulsifier, assistant emulsifier and isotonic agent, wherein the mole ratio of paclitaxel to steroid in the complex is 1:0.2 1/4 4; preferably 1:0.25-2. Said submicron emulsion is useful for the treatment for malignant tumor. The average particle diameter of the submicron emulsion is less than 400 nm and the pH Value is 3.5-6.