Objective A finite element simulation analysis of a bracketless orthodontic appliance was carried out to determine the correction amount under different working conditions. A design scheme for the bracketless orthodontic appliance was also formulated to create an orthodontic appliance formed by the fused deposition process with a personalized orthodontic effect. Methods Combined with the computed tomography data of the patient, a tooth model was reversely reconstructed. The correction amount of the tooth under tilting, twisting, and translation working conditions was established using the finite element method. Materials with different elastic moduli were chosen to make three-dimensional (3D) shaped bracketless orthodonitc appliance, and the orthodontic force was measured. Results Different correction amounts could be designed according to different working conditions so that the orthodontic appliance had a personalized treatment effect. The orthodontic force of the bracketless orthodontic appliance increased with elastic modulus and thickness. Under the given working conditions, the orthodontic force was minimal (90 mN) when the orthodontic material was at the minimum (90 mN). The orthodontic force reached its maximum value when the orthodontic material was at the maximum (61.66 N). Conclusions According to the patient’s tooth condition and the size of the orthodontic force required for each step of correction in the whole correction process, the design should consider bracketless orthodontics with different elastic moduli and thicknesses to treat deformed teeth to realize the effect of staged orthodontic correction.