Objective Finite elemental analysis of the mechanical characteristics of a first mandibular implant molar under different mandibular plane angles determines the load conditions on the implant, thereby providing guidance for clinical application.Methods CT data of three mandibular plane angles (low, average, high) were collected. A finite elemental combination model of a dental implant was constructed. The orthogonal experimental research was designed. Results followed data collection and analysis.Results The optimal combination was a low angle, 4.8 mm, and type Ⅱbone. The relations among diameter of the implant, angle of mandibular bone, and bone density were determined.Conclusion Mandibular plane angle influences the stability of a dental implant. Under constant biting force, dental implants bear the stress proportional to the angle, high angles cause high stress, average angles cause average stress, and low angles cause the least stress.