Polysaccharides are natural polymers formed by more than 10 monosaccharide molecules connected by glycoside bonds. The structure is the basis of the biological activity of polysaccharides. The structure of polysaccharides is complex and diverse, and its biological functions are also varied, including the regulation of immunity, anti-tumor, anti-oxidation and hypoglycemia. Therefore, polysaccharides have a broad application prospect in health food and medicine. The food processing technology has great influence on the structure, biological function and solution behavior of polysaccharides. Ultrasonic, microwave and high pressure homogenization treatment can cause degradation of the polymers, thus affecting the biological function and rheological property of the polysaccharides. This review focuses on the effects of processing technology on the structure-activity relationship and solution behavior of polysaccharides, which will provide the guidance for the exploitation and application of polysaccharides.