Objective To establish a postoperative cognitive dysfunction(POCD) model in aging rats and evaluate the model's quality through intragastric administration of Dendrobium nobile extract. Methods Thirty 4-month-old SD rats were selected to construct an aging rat model by subcutaneous injection of 10 % D-galactose in their neck and back. The injection dose was set to 0.125 g·kg-1·d-1 for 42 consecutive days. The successfully constructed aging rats were randomly divided into three groups: control group, POCD group and POCD treatment group, with 10 rats in each group. The POCD group and the POCD treatment group underwent unilateral nephrectomy under the condition of 3.2 % sevoflurane anesthesia to establish a POCD model in aging rats, while the rats in the control group did not undergo any treatment. After 2 hours of recovery from anesthesia, the POCD treatment group was treated with Dendrobium nobile decoction at a dose of 10 g·kg -1·d -1. The control group and the POCD group were given an equal volume of normal saline, and the gavage operation continued for 14 days. Morris water maze experiment was employed to gauge the learning and memory faculties of rats in every group. Balance beam experiment was carried out to gauge the balance and motor coordination aptitudes of rats in each respective group. The contents of NSE and S-100β in serum were detected by ELISA. HE staining was utilized to observe the morphological alterations of hippocampal neurons in rats. Results In the water maze experiment, the POCD group exhibited a marked decrease in both the duration of retention in the third quadrant and the frequency of effective platform entries, when compared with the control group and the POCD treatment group, and the statistical significance of this difference was evident(P<0.05). In the balance beam experiment, when compared to the control group and the POCD treatment group, the aging rats in the POCD group exhibited a significant prolongation in both the starting time and the time taken to cross the beam, and this disparity was statistically significant(P<0.05). ELISA results indicated that, in comparison with the control group and the POCD treatment group, the aging rats in the POCD group had a significant increase in serum NSE and S - 100β levels, and the statistical significance of this difference was evident(P<0.05). HE staining results revealed that the hippocampal neurons in the POCD group presented distinct pathological alterations. The cellular structure was indistinct, with a chaotic and loose arrangement. There was a marked decrease in the number of cells. The cell morphology was irregular, and the nuclei were pyknotic, exhibiting a high-intensity staining. Additionally, the cytoplasmic boundaries were unclear.Conclusion The aging rat POCD model was successfully established by using the multifactorial method of ‘10% D-galactose 0.125 g·kg -1·d -1 subcutaneously injected into the neck and back of the 4-month-old SD rats for 42 days and unilateral nephrectomy under 3.2% sevoflurane anesthesia’, this method can provide a reliable animal model for the future research of using our traditional medicine to treat POCD