Ainsliaea acerifolia leaves are registered with the Ministry of Food and Drug Safety as edible herbal materials in Korea, and research is underway to explore their potential in developing functional foods, cosmetics, and pharmaceuticals. In this study, we developed an analytical method using HPLC-DAD to quantify three key compounds—chlorogenic acid, isochlorogenic acid A, and 1,5-dicaffeoylquinic acid—in A. acerifolia leaves extract. This method has been optimized and validated for specificity, accuracy, precision, limit of quantification (LOQ), and linearity. The correlation coefficients (r²) for the calibration curves exceeded 0.9962. The limits of detection (LOD) and quantification (LOQ) were 0.3012 and 0.9128 μg/mL for chlorogenic acid, 0.1182 and 0.3582 μg/mL for isochlorogenic acid A, and 0.2342 and 0.7098 μg/mL for 1,5-dicaffeoylquinic acid, respectively. The net recovery rates for accuracy testing were 105.13% for chlorogenic acid, 105.37% for isochlorogenic acid A, and 100.37% for 1,5-dicaffeoylquinic acid. All parameters assessed with this newly developed method fell within the acceptable ranges specified by ICH guidelines. These findings demonstrate that the method is robust and reliable for accurately identifying and quantifying chlorogenic acid, isochlorogenic acid A, and 1,5-dicaffeoylquinic acid in both routine analysis and large-scale extraction process of A. acerifolia leaves.