The invention discloses a temperature-resistant microemulsified methanol diesel oil which consists of 65-70% of diesel oil, 10-15% of water, 2-5% of methanol, 8-10% of emulsifier, and 5-10% of cetane number enhancer; the emulsifier consists of the following components in percentage by mass: 15-25% of yeast, 15-25% of enzymes in flour, 5-15% of sodium dodecyl benzene sulfonate, 5-15% of fatty alcohol-polyoxyethylene ether, 5-15% of anhydrous ethanol, 5-10% of urea, 1-5% of dimethylformamide, 1-5% of potassium hydroxide and 5-10% of cyclohexylamine. A preparation method of the methanol diesel oil comprises the following steps of: preparing the cetane number enhancer and the emulsifier respectively, taking an approximate amount of obtained cetane number enhancer, the emulsifier, the diesel oil and water and then mixing and stirring with the methanol for 40 minutes, and standing for 4 hours. The microemulsified methanol diesel oil has the characteristics of quietness, dispersity, antioxidantion, anticorrosion, defoaming, pour point reduction and the like, thereby being suitable for alpine regions; and in addition, a pour point can reach less than minus 30 DEG C, and the temperature-resistant microemulsified methanol diesel oil can not be layered and emulsified after the long-time storage, so that the methanol diesel oil can essentially reach standards of a national standard diesel oil.