Promethazine hydrochloride has good effects on skin, ear, nose, and throat, as well as internal medicine diseases. Therefore, it is widely used in clinical pediatrics. Due to its large size, the use of this drug in clinical pediatric medicine is limited to some extent. Excessive content of promethazine hydrochloride tablets can easily cause adverse reactions, so it is necessary to analyze the content of promethazine hydrochloride tablets in order to adjust the medication deviation. High performance liquid chromatography can combine pharmacokinetics to analyze the actual content of drugs. With its advantages of high sensitivity and specificity, it has been widely applied in drug analysis in recent years. High performance liquid chromatography is based on the application scope of drugs, forming a comprehensive chromatographic drug analysis plan, timely adjusting chromatographic phase changes, and conducting scientific evaluations to enhance separation efficiency and accurately determine drug content, in order to optimize the application of drug components in high-performance liquid chromatography analysis. This study mainly reviews the research on the determination of the content of promethazine hydrochloride tablets in children's medication by high-performance liquid chromatography, in order to provide reference for the rational use of drugs in pediatric clinical practice.