Abstract: In order to systematically investigate the changes in the bitterness and astringency of Enshi Yulu under varying withering process conditions, as well as to analyze the correlation between key flavor factors, a comprehensive study was conducted. Enshi Yulu, a distinctive steamed green tea native to Enshi Prefecture, is characterized by its vibrant green color, fresh aroma, and smooth taste. However, achieving a balance between reduced bitterness and preserved green characteristics remains a significant challenge in its production. This study addresses this challenge by employing a combination of orthogonal experimental design and high-performance liquid chromatography (HPLC) to determine the contents of catechins and caffeine in fresh tea leaves. Furthermore, Response Surface Methodology (RSM) was applied to optimize the withering parameters, and the relationships among flavor factors were visualized using a chord diagram, providing a novel perspective on their interconnections.The results indicated that catechin content varied significantly under different withering conditions (P = 0.0020), while caffeine content showed no statistically significant changes (P = 0.1713). The optimal withering parameters were identified as an initial moisture content of 77.07%, a withering temperature of 25.49 °C, relative humidity of 60.24%, and wind velocity of 0.54 m/s. Under these conditions, the ratio of non-ester catechins to ester catechins (NETCAT/ETCAT) reached 0.5041, effectively reducing the bitterness of the tea soup and contributing to a smoother and more refined flavor profile. This ratio emerged as a critical indicator of flavor harmony, providing a quantitative basis for optimizing taste attributes.Visualization of the interrelationships among flavor factors using a chord diagram revealed strong correlations between NETCAT/ETCAT and specific catechins. Among these, the most pronounced correlations were observed with EGCG (epigallocatechin gallate, R = 0.990) and ECG (epicatechin gallate, R= 0.918), followed by EGC (epigallocatechin, R= 0.753). These findings underscore the importance of catechin composition in influencing the sensory properties of Enshi Yulu tea. The results further suggest that a well-balanced catechin profile can mitigate bitterness while maintaining the green and fresh characteristics that define this tea.The study highlights the critical role of withering conditions in modulating the chemical composition of tea leaves and their subsequent impact on sensory quality. By combining advanced analytical methods such as HPLC and RSM with data visualization techniques, this research bridges traditional tea processing craftsmanship with modern scientific approaches. This integration provides actionable guidelines for practitioners seeking to improve the quality and market competitiveness of Enshi Yulu tea. Additionally, the methodology developed in this study serves as a valuable reference for optimizing other varieties of steamed green tea, thus contributing to the broader field of tea science and technology.Beyond its immediate findings, this research opens avenues for further exploration. Future studies could focus on the interactions between catechins and other flavor-related compounds, such as amino acids and volatile aroma substances, to gain a more holistic understanding of flavor formation. Incorporating advanced sensing technologies for real-time monitoring of temperature, humidity, and chemical composition during withering could also enhance precision and reproducibility. Moreover, the application of artificial intelligence and machine learning algorithms in data analysis could further refine process optimization, paving the way for intelligent tea production systems.In conclusion, this study not only advances the scientific understanding of the chemical dynamics involved in the withering process of Enshi Yulu tea but also provides a robust framework for integrating modern technology with traditional tea production techniques. By addressing the dual objectives of reducing bitterness and preserving green characteristics, it lays the foundation for innovation in tea processing, enhancing both quality and consumer satisfaction. These insights hold significant implications for the sustainable development and global promotion of Enshi Yulu tea, a cultural treasure with economic and gastronomic value.