Objective To improve fluid management outcomes in postoperative patients after cardiac surgery and to promote patient recovery.Methods A total of 95 patients who underwent cardiac surgery under cardiopulmonary bypass were divided into a control group of 48, receiving usual fluid management, or an intervention group of 47, receiving fluid management using non-invasive cardiac output monitoring in combination with cardiac ultrasound.Results Compared with the control group, the intervention group had significantly shorter endotracheal intubation time, mechanical ventilation time and length of stay in the ICU, higher LVEF and lower NT-proBNP at discharge from the ICU, increased lactate clearance and postoperative urine volume, as well as reduced rate of use of diuretics （all P＜0.05）.Conclusion Combination use of non-invasive cardiac output monitoring and cardiac ultrasound in fluid management in patients undergoing cardiac surgery can effectively improve cardiac function and shorten mechanical ventilation time, resulting in beneficial effects on patient recovery.