Background: Postoperative fluid management is vital for preventing perioperative morbidity and mortality in high-complexity advanced ovarian cancer surgery. We investigated the feasibility and benefits of restrictive fluid therapy on postoperative recovery. Methods: Patients with advanced ovarian cancer who underwent open radical surgery were randomized into the restrictive or liberal fluid group. The endpoints were the length of hospital stay post-surgery and the incidence of complications within 30 days. Results: The restrictive and liberal fluid regimen groups included 30 and 41 patients, respectively. The length of hospital stay was 16.5-days and 21.0-days for the restrictive and liberal group, respectively (p = 0.035). Multiple linear regression analysis showed that length of hospital stay was 2.971-days shorter in the restrictive group than in the liberal group (95% confidence interval (CI): –5.818~–0.124, p = 0.04). The incidence of complications at the end of 30 days was significantly lower in the restrictive group than in the liberal intravenous group (26.7% versus 51.2%; p = 0.032). Adjusted logistic regression demonstrated that restrictive group could significantly reduce the risk of postoperative complications by 68% (Odds Ratio 0.32, 95% CI: 0.11–0.91, p = 0.033). Conclusions: Restrictive fluid management after high-complexity advanced ovarian cancer surgery can significantly decrease the risk of major postoperative complications and facilitate postoperative recovery.