The effects of different mass concentrations of Pholiota nameko polysaccharides on pasting， rheological， texture， thermodynamic properties and microstructure of corn starch were studied. To explore the interaction mechanism between polysaccharides and corn starch and reveal the dose-effect relationship between polysaccharides and starch quality.The results showed that Pholiota nameko polysaccharide could improve the viscosity and gelatinization temperature of the compound system， indicating that the polysaccharide delayed the gelatinization process. When the mass concentration of Pholiota nameko polysaccharides was 0.9 g/mL， the breakdown value of the compound system was 1.77 mPa·s， the setback value was 3.63 mPa·s and the gelatinization enthalpy was 3.95 J/g， indicating that the anti-aging effect and stability of the compound system were the best. With the increase of polysaccharide mass concentration， the viscoelasticity and pseudoplasticity of the complex system gradually increased， and the flow index gradually decreased. Fourier transform infrared spectroscopy analysis showed that the interaction between the polysaccharides and corn starch was through hydrogen bond， and the hydrogen bond interaction was the strongest when the polysaccharide mass concentration was 0.9 g/mL. The results of cryo-electron microscopy showed that the microstructure of the compound system was honeycomb with uniform pores when the polysaccharide mass concentration was 0.6 g/mL.