In this study, a new type of construction material, iron tailings-based rubber concrete (ITRC), was innovatively prepared from waste tire rubber powder and iron tailings. The effects of rubber particle size, soaking agent usage, and silane coupling agent grafting on the fluidity, compressive strength, flexural strength, and flexural-compression ratio of ITRC were investigated in depth. The intrinsic mechanism of rubber powder on the improvement of ITRC properties was revealed by advanced analytical techniques such as micromorphology analysis. It was found that pre-soaking of rubber powder in acidic potassium permanganate (KMnO4) solution followed by silane coupling agent treatment significantly improved the compatibility and bonding effect at the interface between the rubber powder and ITRC, and effectively reduced the generation of microcracks in the matrix. Under the condition of an 82∶18 mass ratio of iron tailings to cement, 1wt% rubber powder doping, and an 18% water-to-cement ratio, the 28 day compressive strength of ITRC reached 32.8 MPa, and the flexural strength reached 5.1 MPa, which increased the compressive strength by 28.6% and the flexural strength by 21.4% compared with that of pure iron tailings cement material. This study not only provided a scientific basis for the recycling of iron tailings and waste tires but also provided a new idea for the accelerated recycling of solid waste. The research results helped to promote the development of environmentally friendly building materials, promoted the recycling of resources, and were of great significance in realizing the green transformation of the construction industry. Through this study, it could be seen that waste materials could be transformed into new materials with practical value through scientific methods and innovative technologies, which not only reduced environmental pollution but also opened up a new way for the sustainable use of resources. The successful preparation and optimization of the properties of ITRC demonstrated the possibility of realizing the dual goals of waste utilization and environmental protection in the construction field. This research result had important theoretical and practical value for promoting the sustainable development of the building materials industry.