With the development of digital technology, digital concrete as an innovative material has attracted widespread attention in the field of construction. Based on digital technology and combined with the characteristics of concrete materials, a method combining numerical simulation and experimental verification is used to investigate the mix design of digital concrete. In this paper, the CDP model was used to adopt the concrete constitutive relationship given in the “Code for design of concrete structures” and it was demonstrated through digital simulation that the number n of microcapsules intersecting with any fracture surface of concrete is proportional to the volume fraction φ of microcapsules, and inversely proportional to the radius r of microcapsules. Therefore, theoretically, increasing the volume fraction of microcapsules or reducing the radius of microcapsules while keeping the volume fraction constant can effectively increase the probability of intersection between cracks and microcapsules; the smaller the diameter of microcapsules, the more intersections with the section, the more dispersed the section distribution, which can ensure the core material fully diffuses into the crack section, making the reaction between the core material and the cement matrix more sufficient, thereby enhancing the repair effect.