Abstract: A one-pot method is used to prepare a fused pyrazole-type compound substituted at nitrogen on 2-position, specifically an indazole-type compound substituted at nitrogen on 2-position. In the method, after azidizing a halogen in a substrate, without post-processing, R-NH2 can be directly added to proceed a ring-closing reaction with an aldehyde group, so as to give the fused pyrazole-type compound substituted at nitrogen on 2-position. For example, by using 2-fluoro-4 methoxy-5-nitro benzaldehyde as a raw material, the indazole-type compound substituted at nitrogen on 2-position can be obtained via azidation and ring-closing steps, and then a series of indazole derivatives can be produced by means of a hydrogenation reaction and a condensation reaction.