Abstract： Accurate and measurable tooth preparation under the principle of protecting dental tissue, vital pulp and periodontal tissue health is a challenging procedure in esthetic dental restoration. The traditional protocol of tooth preparation often leads to complications after restoration because of the lack of precise preparation control. The pre-operative analysis and design, intraoperative guidance and sequence guidance technology of post-operative prosthesis production, with the target restoration space (TRS) as the core and digital technology as the support technology, embody the numerical requirements of the prosthesis space based on the actual measurement, and will lay the core foundation of the future digital prosthodontics. This paper introduces the new understanding of tooth preparation guidance, the classification and application of digital guides, the practice of micro tooth preparation guided by digital template, and summarizes the development direction of prosthodontics from experience guidance to digital guidance.