NOVELTY - The method comprises adding 4.88g of (4R, 5S, 6S)-3-diethylphosphonoacetic-6-((R)-1-ethoxyl)-4-methyl carbapenem-2-alkene-2-P-nitrophenyl ester and 30ml of anhydrous acetonitrile into a first reserve department, heating the mixture mildly to dissolve anhydrous acetonitrile, adding 1.14 g of 6-sulfydryl-(6, 7-dihydro-5H-pyrazol) (1, 2-a) (1, 2, 4) triazole onium salt, 1.2 ml of diisopropylethylamine and 30 ml of anhydrous acetonitrile into a second reserve department, and dissolving 6-sulfydryl-(6, 7-dihydro-5H-pyrazol) (1,2-a) (1, 2, 4) triazole onium salt.    USE - The method is useful for preparing biapenem using microreaction technology, where the biapenem is useful for: treatment of bacterial meningitis; inhibiting Pseudomonas aeruginosa; and treating chronic bronchitis infection, pneumonia, lung abscess, pyelonephritis, cystitis complexity, peritonitis and uterus annexitis. No biological data given.    ADVANTAGE - The method is capable of economically, simply and efficiently preparing the stable, reliable and non-toxic biapenem with reduced energy consumption and high yield and purity and without environmental pollution.    DETAILED DESCRIPTION - The method comprises adding 4.88g of (4R, 5S, 6S)-3-diethylphosphonoacetic-6-((R)-1-ethoxyl)-4-methyl carbapenem-2-alkene-2-P-nitrophenyl ester and 30ml of anhydrous acetonitrile into a first reserve department, heating the mixture mildly to dissolve anhydrous acetonitrile, adding 1.14 g of 6-sulfydryl-(6, 7-dihydro-5H-pyrazol) (1, 2-a) (1, 2, 4) triazole onium salt, 1.2 ml of diisopropylethylamine and 30 ml of anhydrous acetonitrile into a second reserve department, dissolving 6-sulfydryl-(6, 7-dihydro-5H-pyrazol) (1,2-a) (1, 2, 4) triazole onium salt, conveying the reactive materials in the first reserve department and the second reserve department into a reacting section through a connecting pipe of microreactor to obtain biapenem, where a flow velocity of reactant in the connecting pipe is 4-8ml/min, a temperature is -5 to 0 degrees C, a pressure is 7-10 bar and the time of reactant staying in the reacting section is 1.2-2.5 minutes, performing decompression for the reactant and removing acetonitrile to obtain residue, dissolving the residue into ethyl acetate, washing it with water and 0.1 M of phosphate buffer, drying the organic layer with sodium chloride and anhydrous magnesium sulfate, and reducing pressure to remove ethyl acetate and obtain white solid that is target product. A volume of the reaction section is 1 ml. A length of the connecting pipe is 15 cm.