A preparation method of isopropyl 2-(3-nitrobenzylidene)acetoacetate comprises the following steps: carrying out condensation reaction on 3-nitrobenzaldehyde and isopropyl acetoacetate as initial raw materials by using an organic solvent as a solvent in the presence of catalysts acetic acid and piperidine for 2-8 hours; after carrying out vacuum concentration on the filtrate at 80 ℃ to 2/3-3/4 by volume, cooling to -5-5 ℃ while stirring to crystallize overnight; and filtering, and recrystallizing with isopropanol to finally obtain the isopropyl 2-(3-nitrobenzylidene)acetoacetate.
