Objective To investigate the effects of metaraminol on hemodynamics and tissue oxygen metabolism in elderly patients undergoing total knee arthroplasty and cement implantation. Methods Sixty elderly patients undergoing unilateral cement total knee arthroplasty were randomly divided into control group (group C) and metaraminol infusion group (group S) with 30 cases in each group by random numerical table method. The patients in Group S received intravenous infusion of metaraminol 0.03-0.3 ug/kg/min while group C received saline infusion. Metaraminol (0.1-0.2 mg) should be injected by intravenous, when blood pressure is below 30% of baseline blood pressure during operation. Mean arterial pressure (MAP), central venous pressure (CVP) and heart rate (HR) were measured before cement implantation (T0), 5 minutes (T1), 10 minutes (T2) and 30 minutes (T3) after cement implantation in both two groups. Blood samples of arterial blood and central venous blood were collected for blood gas analysis, arterial blood lactate concentration (Lac), hemoglobin volume (Hb), arterial partial pressure of oxygen (PaO2), central venous oxygen saturation (ScvO2), and partial pressure of central venous oxygen (PcvO2) were recorded. According to Fick formula, arterial oxygen content (CaO2), central venous oxygen content (CcvO2), arterial venous oxygen difference (Da-cvO2), and oxygen uptake rate (ERO2) were calculated. Perioperative arrhythmia of lead II electrocardiogram and postoperative nausea and vomiting were recorded. Results Compared with group C at T0, MAP, PaO2, PcvO2, ScvO2, Lac, CaO2, and CcvO2 of patients decreased, and HR, Da-cvO2, and ERO2 increased at T1 and T2 in group C. Compared with group C, MAP, PaO2, PcvO2, ScvO2, Lac, CaO2, and CcvO2 of patients increased, and HR, Da-cvO2, and ERO2 decreased at T2 in group S. Compared with group C, the incidence of intraoperative arrhythmia and postoperative nausea and vomiting decreased in group S. Conclusion Metaraminol improves the hemodynamic changes caused by cement implantation during total knee arthroplasty in elderly patients, and effectively ensures tissue oxygen metabolism.