Accurate diagnosis and surgical selection of the double-outlet right ventricle (DORV) is both critical and difficult. Virtual models and three-dimensional (3D) printing have been used to provide morphological copies to doctors as reference. However, the existing methods have shortcomings in visualization of the surgical results, optimal surgical design, and accurate surgical scheme measurements. To overcome this problem, we performed surgical predictions by designing the intraventricular baffle and ventricular septal defect patch to evaluate surgical options and using 3D printing to guide the trimming of the baffle or patch. A complete set of processes including scanning, modeling, designing, 3D printing, and guiding the trimming of the baffle for the diagnosis and surgical planning of DORV was established. Six cases were used to evaluate the feasibility of this method. The average rate of misdiagnosis of the six cases by computed tomography and echocardiography was 42.5%, which was reduced to 4.6% when the diagnosis was established using the virtual models and 3D printing as auxiliary tools. The approach effectively improved diagnostic accuracy, guided the operation, and simplified the process of patch trimming. The proposed method can thus be used for improving the surgical simulation and guiding of the DORV surgery.