The crown-to-root ratio of natural teeth is of great clinical significance for evaluating the long-term prognosis of natural teeth. However, numerous clinical studies and animal experiments have shown that the crown-root ratio theory of natural teeth does not apply to dental implant prosthesis. Traditional implant theory advocates the application of longer implants to improve success rates, With the popularity of short implants, the influence of the crown-to-implant ratio (C/I) on prosthetic complications has become a new research focus. Through a systematic review and analysis of recent domestic and international literature, this paper investigates the effect of the C/I on the clinical complications and success rates of dental implant prosthesis. The results show that there is no clear correlation between the C/I and implant clinical complications or success rates, but an excessively high ratio may increase the risk of biological and mechanical complications. Clinicians should formulate individualized treatment plans when using short implants, optimizing the C/I to reduce the risk of complications and ensure the long-term stability of single-crown restoration.