Objective To explore the influence of hemodiafiltration (HDF) and hemodialysis (HD) in series with hemoperfusion (HP) on nutritional status and microinflammatory state in elderly patients undergoing maintenance hemodialysis (MHD). Methods 102 elderly patients with MHD who received treatment in hemodialysis center of department of nephrology of our hospital were selected and randomly divided into control group and observation group with 51 cases in each group. The control group was treated with HDF, while the observation group was given HD in series with HP. Serum iron metabolism indicators ［serum iron (SI), total iron binding capacity (TIBC), serum iron saturation (ISAT)］, nutrition-related biochemical indicators ［albumin (ALB), prealbumin (PA), transferrin (TRF) and hemoglobin (Hb)］, micro-inflammatory indicators ［high-sensitivity C-reactive protein (hs-CRP), procalcitonin (PCT) and interleukin-6 (IL-6)］ and expression levels of serum CD14 and CD64 were compared between the two groups before and after treatment. Results After treatment, the levels of serum SI, TIBC, ISAT, ALB, PA, TRF and Hb in the two groups showed significant upward trends compared with those before treatment (P＜0.05), and the levels in observation group were significantly higher than those in control group (P＜0.05). The levels of serum hs-CRP, PCT, IL-6, CD14 and CD64 in both groups showed significant downward trends after treatment compared to before treatment (P＜0.05), and the observation group had significantly lower levels (P＜0.05). Conclusion Compared with HDF treatment, HD in series with HP treatment in elderly MHD patients can better improve the iron metabolism, nutritional status and microinflammatory state, and reduce serum CD14 and CD64 to improve the prognosis of patients