Benzyl quinoline quaternary ammonium salt (BQC) is a commonly used main agent for acidification and corrosion inhibition, but most of the studies are based on the properties of the main product crude and compounding, etc., and the specific roles between the components are not clear. In this paper, benzyl quinoline quaternary ammonium salt crude product (BQC-1) was synthesized by using benzyl chloride and quinoline as raw materials, and recrystallization of BQC-1 was carried out to obtain benzyl quinoline quaternary ammonium salt pure product (BQC-2). The inhibition properties of BQC-1, BQC-2 and their components were evaluated by the static weight loss method, and their compounding properties were investigated. Among them, the corrosion inhibition performance of BQC-1 was much higher than that of BQC-2 as well as the initial raw materials (quinoline and benzyl chloride), indicating that BQC-2 did not play a key role in the benzyl quinoline quaternary ammonium salt inhibition system. Meanwhile, the synergistic and synergistic performance of different compounding agents on BQC-1 was investigated, and a compounding inhibition system was preferred: 0.5% BQC-1 + 0.25% hexaminee + 0.1% KI, which has economic and efficient inhibition performance.