Objective To discuss the application of 3D printing technology in the adjuvant treatment of complex Stanford type B aortic dissection(SBAD)and abdominal aortic aneurysm.Methods The clinical data of 64 patients with complex SBAD and 64 patients with abdominal aortic aneurysm,who were admitted to the Mianyang No.404 Hospital of China from January 2022 to January 2024,were retrospectively analyzed.Of the 64 patients with complex SBAD,33 received preoperative 3D printing adjuvant treatment(observation group Ⅰ)and 31 received preoperative routine examination(control group Ⅰ).Of the 64 patients with abdominal aortic aneurysm,32 received preoperative 3D printing adjuvant treatment(observation group Ⅱ)and 32 received preoperative routine examination(control group Ⅱ).The changes in left-right diameter(LR)and anterior-posterior diameter(AP)of anatomical structure in observation group Ⅰ and observation group Ⅱ were analyzed.The perioperative situations were compared between observation group Ⅰ and control group Ⅰ,as well as between observation groupⅡ and control group Ⅱ.Results In patients with complex SBAD,LR of descending aorta diaphragm in S2(STL model)was significantly higher than that in S1(CTA image)and S3(plastic model,P＜0.05),and AP of descending aorta diaphragm in S2 was higher than that in S3(P＜0.05).LR of brachiocephalic trunk in S3 was significantly lower than that in S1 and S2(P＜0.05),AP of brachiocephalic trunk in S3 stage was significantly higher than that in S1 and S2(P＜0.05),and AP of brachiocephalic trunk in S2 was higher than that in S1(P＜0.05).LR of left common carotid artery in S3 was significantly higher than that in S1 and S2(P＜0.05),LR of left common carotid artery in S2 was higher than that in S1(P＜0.05),and AP of left common carotid artery in S3 was lower than that in S1(P＜0.05).LR and AP of left subclavian artery in S3 were significantly higher than those in S1 and S2(P＜0.05).In patients with abdominal aortic aneurysm,LR and AP of tumor neck in S3 were significantly higher than those in S1(P＜0.05),and AP of aneurysm neck in S3 was significantly higher than that in S2(P＜0.05).LR and AP of aneurysm in S3 and S2 were significantly higher than those in S1(P＜0.05),and LR and AP of aneurysm in S3 were significantly higher than those in S2(P＜0.05).LR of abdominal aortic bifurcation in S3 and S2 was significantly higher than that in S1(P＜0.05),LR of abdominal aortic bifurcation in S3 was significantly higher than that in S2(P＜0.05),and AP of abdominal aortic bifurcation in S3 was significantly lower than that in S1(P＜0.05).AP of left common iliac artery in S3 was significantly lower than that in S1(P＜0.05).In the observation group Ⅰ,the operation time,endovascular operation time and length of hospital stay were significantly shorter than those in the control group Ⅰ(P＜0.05),and the intraoperative blood loss and used dosage of contrast agent were lower than those in the control group Ⅰ(P＜0.05).In observation group Ⅱ,the operation time,endovascular operation time and length of hospital stay were significantly shorter than those in the control group Ⅱ(P＜0.05),and the intraoperative blood loss and used dosage of contrast agent were lower than those in the control group Ⅱ(P＜0.05).In patients with complex SBAD or abdominal aortic aneurysm,there was no internal leakage or stent displacement at 6 months after surgery.Conclusion Adjuvant treatment with 3D printing technology is helpful for improving anatomical structure measurement of lesion sites in patients with complex SBAD and abdominal aortic aneurysm.Preoperative 3D plastic model preview surgery is helpful for shortening the operation time and length of hospital stay and reducing the used dosage of contrast agent without affecting surgical treatment effect.