【Abstract】 Objective To understand the general situation of early pulmonary edema (PE) after aneurysm subarachnoid hemorrhage (aSAH) by using continuous pulse indicator continuous cardiac output (PiCCO) and observe the blood volume change of patients at early stage after aSAH. Methods From January 2015 to January 2017, the patients in the Neurosurgery ICU ward of Sichuan people's Hospital determined that within 48 hours after the occurrence of aSAH, undergone craniotomy, clipping or intravascular interventional embolization were included in the study. According to the inclusion and exclusion criteria, after the family members signed the informed consent, 80 patients in the study group were divided into the conventional treatment group and the PiCCO monitoring group according to the attached digital table, 40 in each group. The early PE, delayed cerebral ischemia (DCI), daily liquid intake, ICU hospitalization time and total hospitalization time were compared between the two groups. All the patients were followed up for 6 months and were divided into PE group (patients with PE) and non PE group (patients without PE) according to the improved Rankin score (MRS) of neurological function. The MRS scores of PE group and non PE group were compared after 6 months. Results There was no significant difference between the two groups in age, gender, aneurysm location, operation mode, hunt Hess and WFNS (P＞0.05). Compared with the routine group, the incidence of PE in PiCCO monitoring and treatment group was significantly lower (P＜0.05). The daily total liquid intake decreased significantly (P＜0.05), and the length of stay in ICU was shorter (P＜0.05). There was no significant difference in the incidence of DCI between the two groups (P＞0.05). There was a significant difference in Mrs scores between non PE group and PE group (P＜0.05). Conclusion PiCCO monitoring and guidance can significantly reduce the incidence of PE in early stage after aSAH, reduce the amount of liquid, shorten the length of stay in ICU and the total length of stay, significantly improve the score of Mrs neurological status after 6 months, and significantly reduce the prognosis of PE patients in early stage.