Objective To analyze the echocardiographic characteristics of above grade 3+ mitral regurgitation (MR) patients by 3D transesophageal echocardiography (3D-TEE) in transcatheter edge-to-edge repair (TEER) and compare the intervention rate of TEER treatment in patients with different risk stratification. Methods We retrospectively analyzed the clinical data of 91 patients with above grade 3+ MR in Anzhen Hospital between June 2021 and April 2022. There were 45 males and 46 females aged 66.5±15.9 years. According to pathogenesis, the patients were divided into different anatomical groups and risk stratification groups. There were 34 patients in a simple degenerative group (simple DMR group), 28 patietns in a complex disease group (Complex group), 14 patients in a simple ventricular functional reflux group (simple VFMR group), 9 patients in a simple atrial functional reflux group (simple AFMR group), and 6 patients in a mixed functional reflux group (mixed FMR group). All patients were examined with a unified standard of transthoracic echocardiography (TTE) and 3D-TEE to compare the characteristic three-dimensional structural changes of the mitral valve in each group. According to the three partition strategy of preoperative anatomical evaluation of TEER, the risk stratification was conducted for the enrolled patients, which was divided into three regions from light to heavy: green area, yellow area, and red area. TEER treatment intervention rate of patients with different risk stratification was calculated. Results Ant leaf angle and post leaf angle were negative in the simple DMR and Complex groups, and non-planar angle, prolapse height and prolapse volume were higher than those of the other groups (P=0.000). Ant leaf angle and post leaf angle were positive in the VFMR group and the mixed FMR group. Anterior and posterior (AP) diameter of valve ring (P=0.036), tenting height and tenting volume were higher than those of other groups (P=0.000). AP diameter, tenting height and tenting volume were changed mildly in patients with simple AFMR. MR patients in red and yellow zone achieved a 28.1% TEER intervention rate.Conclusion Standardized TTE and TEE examinations are crucial for the qualitative and quantitative diagnosis of MR in the echo core-lab. 3D-TEE mitral valve parameter can help determine the exact pathogenesis of MR and to improve the interventional rate of challenging MR patients.