In order to study the effects of phosphorylation and carboxymethylation on the physicochemical properties and hypoglycemic activity of CSP, P-CSP CM-CSP were prepared by using sodium phosphate and chloroacetic acid method respectively. respectively, and their physicochemical properties and hypoglycemic activity were investigated. The results of IR、NMR showed that P-CSP and CM-CSP were successfully prepared; compared with the CSP before modification, the viscosity was reduced, the solubility, the relative molecular mass were increased, and the surface morphology was changed, and the thermal stability was improved; however, the composition of the monosaccharides and the triple-stranded helical structure did not change; in vitro hypoglycemic study showed that 6 mg/mL of CSP, P -CSP and CM-CSP had IC50 of 3.78 mg/mL, 1.94 mg/mL, and 3.82 mg/mL for α-amylase inhibition, and 3.82 mg/mL, 1.98 mg/mL, and 2.12 mg/mL for α-glucosidase inhibition; IR-HepG2 showed an increase in the glucose consumption and liver glycogen results showed that at 2.0 mg/mL, the glucose consumption of CSP, P-CSP, CM-CSP was 6.61 mmol, 8.23 mmol, 7.62 mmol, and the liver glycogen content was 6.31 mg/g, 7.14 mg/g, and 6.52 mg/g, respectively. suggesting that the phosphorylation and carboxymethylation modifications were able to enhance the physicochemical properties and hypoglycaemic activity of Crataegus songarica polysaccharides, which has good potential for application.