Objective To design and optimize the artificial cervical joint complexity.Methods A three-dimension model of the artificial cervical joint complexity was constructed;we meshed the model based on the finite element method.The feature dimension of bone graft cavity in the model was set in a specified varied range.Under the physical load,we operated a simulation to optimize the feature dimension.We analyzed the stress,strain,and had an evaluation on the systematic safety factor.Result The simulation showed that the maximum stress appeared in the central area of the inferior of bone graft cavity,the minimum safety factor appeared in the contact area between the superior disc implant and the pad.As the feature dimension got bigger,the maximum strain increased,the graph of minimum safety factor is a Para-curve.Conclusion Taking the consideration of the systematic constancy and bone graft cavity,the optimal feature dimension of the bone graft cavity is supposed to be 3mm,because the maximum stress becomes the smallest and the systematic safety factor becomes the biggest when the feature dimension is 3mm.