The invention belongs to the technical field of pesticides, and in particular relates to a pyrazole compound or a salt thereof, and a preparation method, a herbicide composition and a use thereof. Disclosed is a pyrazole compound of formula (I) or a salt thereof. In the formula (I), R1 represents a hydrogen atom or C1-C4 alkyl； R2 represents C1-C3 alkyl； R3 represents a C1-C6 linear or cyclic group containing one or more of O, S and N heteroatoms； R4 represents a C1-C3 alkyl or halogen； and R5 represents a pyrazole ring or a pyrazole ring substituted by one or more alkyl, alkoxy, halogen, haloalkyl, amino and nitro groups. The pyrazole compound is a good herbicide with a broad-spectrum bioactivity and outstanding crop safety.
