This study introduces a novel colorimetric method based on ultraviolet/visible spectrophotometry-colorimetry (UV/Vis-CM) for detecting and quantifying total triterpenoids in traditional Chinese medicine (TCM). The method incorporates 2-hydroxy-5-methylbenzaldehyde and concentrated sulfuric acid to enhance sensitivity and accuracy. The reaction mixture is prepared by mixing the reagents at a 1:3 volume ratio, reacting at room temperature for 25 minutes, and then cooling in an ice bath for 5 minutes. The optimal absorption wavelength for detection is determined to be 543 nm for hawthorn leaves and 547 nm for liquorice. The method's accuracy and reliability are validated by comparing it with high-performance liquid chromatography (HPLC) and four other colorimetric methods. The UV/Vis-CM method offers advantages such as no heating requirement, high sensitivity, short usage time, low solvent usage, and low equipment costs. It provides a rapid and reliable tool for on-site testing and large-scale screening of total triterpenoids in TCM, contributing to the modernization of TCM research, quality control, and drug development.This study introduces a novel colorimetric method based on ultraviolet/visible spectrophotometry-colorimetry (UV/Vis-CM) for detecting and quantifying total triterpenoids in traditional Chinese medicine (TCM). The method incorporates 2-hydroxy-5-methylbenzaldehyde and concentrated sulfuric acid to enhance sensitivity and accuracy. The reaction mixture is prepared by mixing the reagents at a 1:3 volume ratio, reacting at room temperature for 25 minutes, and then cooling in an ice bath for 5 minutes. The optimal absorption wavelength for detection is determined to be 543 nm for hawthorn leaves and 547 nm for liquorice. The method's accuracy and reliability are validated by comparing it with high-performance liquid chromatography (HPLC) and four other colorimetric methods. The UV/Vis-CM method offers advantages such as no heating requirement, high sensitivity, short usage time, low solvent usage, and low equipment costs. It provides a rapid and reliable tool for on-site testing and large-scale screening of total triterpenoids in TCM, contributing to the modernization of TCM research, quality control, and drug development.