Abstract Pigments frequently co‐occurred during polysaccharide extraction. The pigment occurrence has significantly hampered the subsequent investigation of polysaccharides. In this work, the pigment of intracellular polysaccharides from Syringa pubescens Turcz flowers were comprehensively investigated. Ten kinds of resin were employed to assess the decolorization efficacy. The data indicated that HPD‐600 had remarkably decolorization ratio and polysaccharides recovery ratio. The decolorization conditions employing HPD‐600 were optimized using the response surface methodology. The optimal conditions of decolorization were a polysaccharide concentration of 5.0 mg/mL, an adsorption time of 3.8 h, an adsorption temperature of 33 °C, and a resin dosage of 20 g. Then, UV spectrophotometry, Fourier transform infrared spectroscopy, and scanning electron microscopy were used to investigate the polysaccharide structure before and after decolorization. High‐performance liquid chromatography analysis was used to explore the antioxidant mechanism of the polysaccharides. The findings obtained from this study provided important perspectives on enhancing the decolorization process of the polysaccharides and facilitate the intensive study and implementation of the polysaccharides from Syringa pubescens Turcz flowers in different fields.