Pregnancy complicated by aortic root aneurysm in patients with Marfan syndrome is one of the main causes of termination of pregnancy or even death in pregnant women. A very small number of pregnant women require cardiac surgery to preserve pregnancy under extracorporeal circulation, and all surgeries use aortic root replacement. We reported a 30-year-old patient with severe aortic regurgitation combined with giant aortic root aneurysm and Marfan syndrome in mid-pregnancy. Valve-sparing root replacement using reimplantation technology was performed via a multidisciplinary cooperation model. This not only achieved the patient’s desire to continue pregnancy but also avoided the anticoagulation and bleeding complications brought by mechanical valve replacement, reduced pregnancy risks and improved long-term quality of life. Postoperative echocardiography showed trace aortic regurgitation, aortic valve coaptation height of 0.6 cm, effective height of 1.1 cm, maximum aortic flow velocity of 1.4 m/s, mean transvalvular pressure gradient of 4.4 mm Hg, and satisfactory clinical results.