Objective Exploring the influence of the shape of the patch of the intraventricular tunnel (IVT) construction on the biomechanical performance of the double outlet right ventricle after correction. Methods Based on the idealized IVT model, a two-dimensional IVT patch was designed. Six groups of patch models were established according to the difference between the long and short axis of the rhombus patch in the turning part, and finite element analysis method was used to numerically simulate the process of stitching, holding and propping up the patch into a three-dimensional IVT model. Results The maximum stress of the suture line of the six groups of patch models are respectively 3.136 MPa, 3.72 MPa, 3.759 MPa, 2.231 MPa, 3.592 MPa, and 3.244 MPa, which are mainly concentrated at the acute-angle corners of the rhombus; the IVT volumes formed are respectively 6504.24 mm3, 6498.71 mm3, 6502.36 mm3, 6505.30 mm3, 6507.28 mm3, 6582.28 mm3; the pressure difference between the two ends of the IVT are respectively 8.35 mmHg, 8.28 mmHg, 7.9 mmHg, 8.16 mmHg, 8.27 mmHg, 8.7 mmHg; the flow rates are respectively 1.67 m/s, 1.666 m/s, 1.627 m/s, 1.647 m/s, 1.669 m/s, 1.7 m/s. Conclusions As the ratio of the long and short axis of the patch increases, the maximum stress of the IVT suture line first decreases and then increases, and the volume shows an increasing trend. The pressure difference between the two ends of the tunnel first decreases and then increases. The patch with the long-to-short axis ratio of 1:0.15 has a uniform surface stress distribution, and the maximum stress value on the suture line is the smallest. At the same time, the right ventricular volume is less encroached on, and the pressure difference at both ends of the tunnel is small, and the suture effect is better.