1-Methyl-3, 4-dinitropyrazole(MDNP) was synthesized using 3-nitropyrazole as starting material via nitration and methylation, and its structrue was characterized by infrared spectrum(IR), proton nuclear magnetic resonance(¹H NMR) and differential scanning calorimetry(DSC).The methylation reaction conditions were optimized.Results show that its thermal decomposition temperature is 298 ℃, and melting point is 20 ℃, having good thermal stability.The optimum conditions of methylation reaction is as follows:the reaction temperature 90 ℃, the reaction time 6.5 h, the molar ratio of 3, 4-dinitropyrazoles, DMC(dimethyl carbonate) to anhydrous potassium carbonate 1:10.5:1.5, and the yield of target product is 55.6%.