Objective To explore the effect of lung water management guided by pulse indicator continuous cardiac output (PICCO) in noninvasive-invasive-noninvasive sequential mechanical ventilation to severe acute pancreatitis (SAP) caused acute respiratory distress syndrome (ARDS).Methods The patients with ARDS caused by SAP in the department of critical care medicine in this hospital from January 2012 to January 2015 were selected as the research subjects and divided into the treatment group (lung water management guided by PICCO) and control group(without lung water management guided by PIC CO) according to different lung water management modes.The noninvasive ventilation time,invasive ventilation time,total mechanical ventilation time,mortality rate,incidence rate of pulmonary edema,incidence rate of ventilator associated pneumonia (VAP) and ICU stay time were compared between the two groups.Results The invasive ventilation time in the treatment group was (3.54 ± 1.78)d,which was lower than (4.31 ±2.42)d in the control group(P＜0.05);the occurrence rate of pulmonary edema in the treatment group was 13.64 ％,which was lower than 35.42％ in the control group;the VAP occurrence rate in the treatment group was 6.82 ％,which was lower than 22.92％ in the control group;the mortality rate was 11.36％,which was lower than 29.17％ in the control group;the ICU stay time was (7.21 ± 1.13)d,which was lower than (8.19 ± 1.28)d in the control group,the differences were statistically significant(P＜0.05).Conclusion The lung water management guided by PICCO in SAP caused ARDS sequential mechanical ventilation is more accurate and effective,which is related to accurate liquid management,conduces to the patient's treatment,and is worthy of popularization and application.