Objective To analyze the influence of bone graft and prosthesis on stress distributions in internal structure and surrounding bone tissues of implant prosthesis. Methods Two models of maxillary central incisor implants supported by two kinds of labial alveolar bone models were established, which were restored by porcelain fused metal (PFM) crown and zirconia all-ceramic crown, respectively. The mechanical loads were applied to analyze the influence of bone graft and two different prostheses on stress distributions of internal structure of the implant and interface between the implant and bone. Results In bone graft group, the stress in labial part of the retaining screw and labial bone tissues of the implant was much lower than that in non-bone graft group, but the stress of the implant neck was higher in bone graft group than that in non-bone graft group. Under the same bone condition, the stress of zirconia all-ceramic crown group on lip side of the retaining screw was greater than that of PFM crown group. Conclusions Prosthesis have little effect on stress distributions of internal structure and surrounding bone tissues of implant prosthesis, but the difference of labial bone affected by bone grafts can affect stress concentrations of the retaining screw and the implant-bone interface.