The present invention belongs to the technical field of pesticide synergists, and in particular relates to a synergistic herbicidal composition containing a 4-benzoylpyrazole compound. Disclosed is a synergistic herbicidal composition, comprising a herbicidally effective amount of active ingredient A and active ingredient B, wherein active ingredient A is a compound (see formula A); active ingredient B may be selected from one or more of the following compounds: 1) phenoxyalkanoic acids; 2) pyridine carboxylic acids; 3) benzoic acids; 4) hydroxybenzonitriles; 5) ureas; 6) pyridines; 7) triazolinones; 8) diphenyl ethers; 9) acetamides; 10) aromatic oxygen-phenoxy group propanonates; 11) cyclohexanediones; 12) sulfonylureas; 13) triazine; 14) sulfonamides; 15) phenyl pyrazoline; and 16) other: bentazone. The composition can effectively prevent and eradicate broad-leaf weeds in wheat fields, has characteristics that extend the weed-controlling spectrum, has a significant synergistic effect, reduces the administered amounts, and is safe for crops, etc.