Abstract：Objective：To observe the preventive and therapeutic effects of external application with Rhei Radix et Rhizoma and Natrii Sulfas combined with microwave therapy administered at different time points for post-cesarean fat liquefaction. Methods：A total of 120 post-cesarean maternal patients with vertical incisions treated at Department of Obstetrics and Gynecology， Xianju People's Hospital from December 2022 to February 2024 were divided into the control group， the observation group 1， and the observation group 2 using the random number table method， with 40 cases in each group. The control group received immediate external application with Rhei Radix et Rhizoma and Natrii Sulfas after operation，microwave therapy at 24 hours and 48 hours after operation，followed by another external application with Rhei Radix et Rhizoma and Natrii Sulfas at 48 hours after operation. The observation group 1 received microwave therapy and external application with Rhei Radix et Rhizoma and Natrii Sulfas at 24 hours post-operation. The observation group 2 received microwave therapy at 24 hours and 48 hours， with external application with Rhei Radix et Rhizoma and Natrii Sulfas at 48 hours after operation. The excellent rate of wound healing were compared among the three groups. At postoperative days 1，3，and 7，the changes in Pressure Ulcer Scale for Healing （PUSH） scores，Generic Quality of Life Inventory-74（ GQOLI-74） scores，hospitalization condition，and interleukin-1β（ IL-1β） and high-sensitivity C-reactive protein （hs-CRP） levels were compared. Results： The observation group 2 showed significantly better wound healing （85.00%， 34/40） compared to the control group （52.50%， 21/40） and the observation group 1 （57.50%， 23/40） （P＜0.05）. PUSH scores decreased while GQOLI-74 scores increased progressively in all groups （P＜0.05） at postoperative days 3，and 7. The observation group 2 demonstrated significantly lower PUSH scores at postoperative days 3 and 7 （P＜0.05）， and higher GQOLI-74 scores at postoperative day 7 compared to the other groups （P＜0.05）， and required fewer dressing changes， incurred lower hospitalization costs， and had shorter hospital stays than the control group and the observation group 1， differences being significant （P＜0.05）. At postoperative day 7，all groups showed reduced IL-1β and hs-CRP levels compared with postoperative day 3（ P＜0.05），and the IL-1β and hs-CRP levels in the observation group 2 were lower than those in the control group and the observation group 1 （P＜0.05）. Conclusion：Microwave therapy at 24 hours and 48 hours post-operation combined with external application with Rhei Radix et Rhizoma and Natrii Sulfas at 48 hours significantly promotes wound healing，reduces inflammation，and decreases the risk of post-cesarean fat liquefaction.