To investigate the mechanical properties and microscopic damage evolution of recycled sand/powder concreteABAQUS based on Python language was used to establish a multi-phase three-dimensional finite element model considering virgin aggregateold/new mortar matrix and corresponding interfacial transition zones. The effectiveness of the model was verified by compressive tests on recycled sand/powder concrete samples. The results show that the microscopic model of recycled sand/powder concrete established in this study efficaciously simulates its mechanical properties and microscopic damage circumstances. The discrepancy between the measured and simulated compressive strength is minimalnot exceeding 1065%. The destruction of recycled sand/powder concrete specimen is generally in an “X” shapewhich is fundamentally consistent with experimental phenomenon. The initial damage emerges in interface transition zone and subsequently develops progressively until it penetrates. As the content of recycled fine aggregate and recycled micro powder increasesthe extent of damage expansion becomes more severeand its mechanical properties correspondingly decline.