Preparation method of pyrazole compound

The invention discloses a preparation method of a pyrazole compound (I), which comprises the following steps: in the presence of an alkaline substance and a catalyst, dissolving a compound as shown in a general formula (II) and a compound as shown in a general formula (III) in a proper solvent, heating, reacting with CO under pressure, and acidifying to obtain the pyrazole compound (I), in the general formulas (I), (II) and (III), R1, R4 and R5 are respectively and independently selected from hydrogen, nitryl, halogen, cyano, formyl, cyanosulfenyl and (C1-C6)-alkyl; r2 and R3 are respectively and independently selected from hydrogen, cyano, formyl, cyano-sulfenyl, (C1-C6) straight chain or branched chain alkyl or halogenated alkyl, phenyl substituted by 1-5 halogens, aryl substituted by 1-5 alkyl or halogenated alkyl and N-containing heterocyclic aryl; r6 is selected from methyl, ethyl and isopropyl; r7 is selected from the group consisting of (C1-C6)-alkyl and (C3-C6)-cycloalkyl; r8 is selected from chlorine