Objective To investigate the application of non-focused planar ultrasound therapeutic device in postoperative cicatricial adhesion. Methods A total of 120 patients with postoperative cicatricial adhesion treated at Fuling ZHOU Yesong Medical Beauty Clinic from January 2025 to June 2025 were selected, and they were divided into the control group and the experimental group by the random number table method, with 60 patients in each group. The control group received routine rehabilitation treatment, and the experimental group was treated with non-focused planar ultrasound therapeutic device on the basis of the control group. The scar improvement, local circulation and swelling, clinical symptom improvement, clinical efffcacy and adverse reactions were compared between the two groups. Results The scar hardness in the experimental group at 2 and 4 weeks after treatment was lower than that in the control group, and the difference was statistically signiffcant (P<0.05). The scar appearance score in the experimental group at 4 weeks after treatment was lower than that in the control group, and the difference was statistically signiffcant (P<0.05). The local blood ffow increase and circumference difference in the experimental group at 4 weeks after treatment were better than those in the control group, and the differences were statistically signiffcant (P<0.05). The VAS scores in the experimental group at 2 and 4 weeks after treatment were lower than those in the control group, and the differences were statistically signiffcant (P<0.05). The spasm frequency in the experimental group at 4 weeks after treatment was lower than that in the control group, and the difference was statistically signiffcant (P<0.05). The total effective rate of the experimental group (95.00%) was higher than that of the control group (81.67%), and the difference was statistically signiffcant (P<0.05). There was no signiffcant difference in the incidence of adverse reactions between the two groups (P>0.05). Conclusion Non-focused planar ultrasound therapeutic device can effectively improve postoperative cicatricial adhesion, promote local blood circulation, relieve swelling, pain and muscle spasm, without increasing the risk of adverse reactions, showing good application value.