Objective To explore the effect of acute normovolemic hemodilution on the indexes of oxygen metabolism and hemodynamics in patients undergoing craniocerebral tumor surgery. Methods A total of 80 cases patients undergoing craniocerebral tumor surgery who were admitted to Mianyang Hospital Affiliated to School of Medicine,University of Electronic Science and Technology of China·Mianyang Central Hospital from January 2021 to December 2022 were divided into the control group and the observation group according to the random number table method, with 40 cases in each group. Patients in the control group were treated with simple controlled hypotension, while patients in the observation group were treated with acute normovolemic hemodilution combined with controlled hypotension, patients in the both groups were followed up until discharge. The levels of oxygen delivery (DO2), oxygen consumption (VO2), oxygen extraction ratio (ERO2), heart rate (HR), mean arterial pressure (MAP), central venous pressure (CVP) after general anesthesia intubation (T0), after acute normovolemic hemodilution (T1), after controlled hypotension (T2), after lesion resection (T3), after surgery (T4) and the amount of blood loss and allogeneic blood transfusion and the levels of blood volum indexes before and one day after surgery and the occurrence of complications of patients were compared between the two groups. Results From T0 to T4 , the DO2 of patients in the observation group decreased first, then increased and decreased again, and the ERO2 of patients in the observation group increased first, then decreased and increased again, and the DO2 of patients in the observation group was significantly lower than that in the control group, the ERO2 of patients in the observation group was significantly higher than that in the control group from T1 to T4 ; there were significant fluctuations in HR, MAP and CVP of patients between the two groups from T0 and T4, and the HR of patients in the observation group was significantly lower than those in the control group from T2 and T4 , and the MAP and CVP of patients in the observation group were significantly higher than that in the control group from T1 to T4; the amount of blood loss and allogeneic blood transfusion of patients in the observation group were lower than those in the control group; compared with before surgery, the levels of hemoglobin, platelet and plasma fibrinogen of patients in the two groups decreased one day after surgery, and the hemoglobin of patients in the observation group was higher than that in the control group one day after surgery; the total complications incidence of patients in the observation group was lower than that in the control group (all P<0.05). Conclusion Acute normovolemic hemodilution combined with controlled hypotension can not only reduce the amount of blood loss and allogeneic blood transfusion during craniocerebral tumor surgery, but also doesn’t affect the body's oxygen consumption, stabilize hemodynamics, promote the recovery of patients' blood volume, and reduce the occurrence of complications.