Objective: To investigate the effect of biological prosthesis hip replacement on hip function and serum inflammation in elderly patients with femoral neck fracture. Methods: A total of 40 elderly patients with femoral neck fracture admitted to the First Affiliated Hospital of Baotou Medical College were selected as the study subjects. The Harris scores before and after hip replacement with biological prosthesis were compared. The incidence of complications after treatment and the changes of serum inflammatory factors interleukin-6 (IL-6) and interleukin-10 (IL-10) before and 3 and 7 days after operation were compared. Results: The Harris score of the patients after 3 months of surgical treatment was significantly higher than that before surgical treatment (P＜0.05). There were 1 case of prosthesis dislocation and 1 case of periprosthetic fracture after operation. The incidence of complications was 5.0% (2/40). Compared with the patients before operation, the serum IL-6 levels at 3 and 7 days after operation showed a significant decrease (P＜0.05), and the serum IL-10 levels showed a significant increase (P＜0.001). Conclusion: For elderly patients with femoral neck fracture, biological prosthesis for hip replacement surgery has fewer complications, and can improve hip function, reduce inflammatory response, and has clinical promotion value.