The aim of the present study was to purify the natural chlorogenic acid (CGA) monomer from Heijingang potatoes and investigate its interaction with recombinant human serum albumin (rHSA). The potato extract (PE) was purified using macroporous resins and solvent, and the CGA monomer was subsequently isolated using semipreparative liquid chromatography (SP-LC). The purity and structure of the CGA monomer was analyzed by high-performance liquid chromatography (HPLC) and nuclear magnetic resonance (NMR). The interaction between the CGA monomer and rHSA was studied using fluorescence spectroscopy and molecular docking. HPLC analysis indicates that the CGA monomer had a retention time of 5.368 min and a purity of 97.9%, the presence of which was confirmed by NMR. The molecular docking and fluorescence spectroscopy demonstrate that CGA had a static quenching effect on rHSA with one binding site, and the range of K values was 7.14 × 10³ to 1.56 × 10⁴ M^-1. This simple and efficient extract coupled with SP-LC has the potential for use in the extraction and purification of CGA in pilot or large-scale operations.