Through the establishment of D-galactose-induced senile osteoporosis (SOP) mouse model， the effect of Grifola frondosa polypeptide-calcium chelate (GPs-Ca) on SOP was explored. The calcium absorption promoting ability of Grifola frondosa polypeptide-calcium chelate was studied by Caco-2 single cell layer model in vitro. Fifty male ICR mice were randomly divided into 5 groups. Except for the blank control group， the other four groups were given intraperitoneal injection of D-galactose； the control group was given intraperitoneal injection of the same dose of normal saline. After 8 weeks， the model was successfully established. Both the control group and the model control group were given deionized water intragastrically； the treated group was given a high dose of Grifola frondosa polypeptide-calcium chelate (Hgps-Ca). After 4 weeks of continuous treated in each group， blood was collected to detect the blood biochemical indicators， and the femur and tibia were stripped to determine the bone indicators. A Caco-2 monolayer was established， and Fluo-3-Am calcium ion probe was used to measure intracellular calcium uptake. Serum calcium and phosphorus levels in the Hgps-Ca group increased significantly， with statistical significance (P<0.05)； serum alkaline phosphate (ALP) values of each group were lower than those in the model group， and the serum ALP level of Hgps-Ca group was close to that of the control group. GPs-Ca was more easily absorbed and transported in cells than inorganic calcium. The results showed that Grifola frondosa polypeptide-calcium chelate can improve serum calcium， phosphorus， CAT levels， reduce ALP activity， promote calcium salt deposition， improve calcium absorption and utilization rate， which is conducive to the treatment of SOP.