Abstract: Litchi pomace, an underutilized byproduct of litchi processing, is rich in dietary fiber and polyphenols. To achieve comprehensive high-value utilization, this study established a process system for the simultaneous preparation of four key components from litchi pomace: free phenolics, bound phenolics, dietary fiber (LTDF), and de-phenolic dietary fiber (LTDF-F). These components were systematically extracted, purified, and functionally evaluated. The results showed that the extraction yields of LTDF and LTDF-F from litchi pomace were 58.55% and 53.05%, respectively. Polyphenol analysis revealed that the content of bound phenolics in litchi pomace (26.23±0.57 mg GAE/g DW) was significantly (P<0.05) higher than that of free phenolics (8.54±0.21 mg GAE/g DW). Further quantification by HPLC identified quercetin-3-O-rutinoside-(1→2)-O-rhamnoside (1.2493±0.0307 mg/g DW) and procyanidin B₁ (1.7960±0.0390 mg/g DW) as the predominant monomers in free and bound phenolics, respectively. In vitro antioxidant studies demonstrated that both free and bound phenolics exhibited significant antioxidant activity, with key monomers such as procyanidin B₁ (DPPH IC₅₀=0.0184±0.0016 mg/mL) and catechin (DPPH IC₅₀=0.0085±0.0004 mg/mL) showing excellent antioxidant capacity, thereby confirming the overall value of polyphenol component development. Structural analysis of the dietary fibers indicated that de-phenolic treatment did not significantly alter the main structure of the fibers. However, functional comparison revealed that LTDF significantly (P<0.05) outperformed LTDF-F in terms of hydration capacity as well as adsorption capacity for glucose, cholesterol (pH 7.0), and nitrite (pH 2.0), directly demonstrating that phenolic substances play a crucial role in enhancing the functional properties of dietary fiber. This study confirms that the four components—polyphenols and dietary fibers found in litchi pomace—each exhibit distinct functionalities, collectively establishing litchi pomace as a viable functional food ingredient. The findings offer significant theoretical and technical support for the comprehensive, zero-waste utilization of byproducts from litchi processing.