Objective This study aimed to explore the relationship between the parameters of the LAA orifice based on three-dimensional transesophageal echocardiography (3D TEE) data and the final decive size of LAmbreTM. Methods We retrospectively analyzed ultrasound 3D DICOM data from 23 patients who underwent LAA occlusion with the LAmbreTM occluder. The volume images of LAA were acquired by the post-processing of Mimics software. The parameters of the LAA orifice were measured and evaluated. Two cases of LAA who had been replaced occluders during LAA occlusion were printed, and simulation operations were carried out on these models. Results The data of 23 patients were successfully post-treated and five parameters of the LAA orifice were obtained. Correlation between the maximal width, area and perimeter measurements and the closure disk of the LAmbreTM device were r=0.85, P=0.000, r=0.74, P=0.000, r=0.89, P= 0.000, respectively. By comprehensive analysis of the LAA orifice parameters, the two occluders finally used for simulation were selected, which had the same size as the occluder chosen for the actual procedure, and were inserted into 3D printing models with a near perfect fit. Conclusions Comprehensive analysis of the anatomical parameters of the LAA orifice by ultrasound 3D DICOM data may better guide the choice of optimal device size LAmbreTM.