Objective This study aims to explore the application of gel permeation chromatography in determining the content of xylene-soluble substances in polypropylene. Methods The study employed gel chromatography to accurately measure the content of xylene-soluble substances in polypropylene and conducted a comparative analysis with the volumetric method to verify the accuracy and reliability of gel chromatography. Results The experimental results indicated that the absolute difference between the measurement results obtained by gel chromatography and the volumetric method did not exceed 0.07%, meeting the accuracy requirements. Furthermore, gel chromatography significantly shortened the analysis time from approximately 8 hours with the volumetric method to 3 hours, and the operation was more straightforward. The amount of xylene used during sample processing was greatly reduced, demonstrating its efficiency and environmental friendliness. Conclusion This study successfully validated the feasibility and superiority of gel chromatography in determining the content of xylene-soluble substances in polypropylene. This method is not only simple to operate and fast in analysis but also highly environmentally friendly, with minimal impact on the environment and operators. It provides strong support for the rapid detection and control of polypropylene product quality and holds broad industrial application prospects.