Objective To explore the efficacy of electric spiral knife combined with negative-pressure liposuction for dorsocervical fat accumulation. Methods A total of 86 patients with dorsocervical fat accumulation treated at Shanghai Second People’s Hospital from May 2024 to May 2025 were selected, and they were divided into the study group and the control group according to different treatment methods, with 43 patients in each group. The control group was treated with negative-pressure liposuction alone, and the study group was treated with electric spiral knife combined with negative-pressure liposuction. The intraoperative indicators, postoperative recovery, contour improvement, complication rate and aesthetic satisfaction were compared between the two groups. Results The operation time of the study group was shorter than that of the control group, the intraoperative blood loss was less than that of the control group, and the liposuction volume was higher than that of the control group (P<0.05). The swelling regression time, wound healing time and hospitalization time of the study group were shorter than those of the control group (P<0.05). The height of the nuchaldorsal bulge and the thickness of the fat layer in the study group at 3 months after operation were lower than those in the control group (P <0.05). The incidence of complications in the study group (2.33%) was lower than that in the control group (13.95%) (P <0.05). The aesthetic satisfaction score of the study group was higher than that of the control group (P <0.05). Conclusion Electric spiral knife combined with negative-pressure liposuction achieves reliable effects for dorsocervical fat accumulation. It features shorteroperative time, less intraoperative bleeding, sufficient fat removal and rapid postoperative recovery. Furthermore, it achieves favorable contour improvement, has a low incidence of complications, and results in high patient aesthetic satisfaction.