Abstract: Aiming at the problems of insufficient toughness and frequent cracking of shotcrete used for underground mine roadway support, this paper proposes a high-toughness cementitious composite for mining applications, using metal mine tailings as aggregate, Portland cement, blast furnace slag and silica fume as cementitious materials, and polyethylene（PE） fibers as reinforcing material. To verify the mechanical performance advantages of this new support material, a total of 185 standard specimens are prepared with four variables, namely tailings type（copper-nickel mine tailings and gold mine tailings）, water-binder ratio（0.22, 0.24 and 0.26）, fiber length（6 mm, 12 mm and 18 mm） and curing age（7 d, 14 d and 28 d）. Uniaxial tensile, compressive and shear tests are carried out on all specimens, and scanning electron microscopy（SEM） is adopted to characterize the microstructure of the proposed material. The results show that fiber-reinforced cementitious composites using copper-nickel total mine tailings and gold total mine tailings as aggregate exhibit significant strain-hardening behavior. At the curing age of 28 d, their tensile strengths reach 2.87 MPa and 2.22 MPa, with corresponding tensile strains of 7.84% and 8.28%, respectively, both superior to those of conventional shotcrete. The compressive strength of the proposed composites increases with curing age, with the maximum average compressive strengths of 16.23 MPa at 7 d and 45.66 MPa at 28 d. Differences in mineral composition and particle size of aggregates alter the hydration process of matrix and the interfacial microstructure. The cohesion and internal friction angle of fiber-reinforced composites prepared from different tailings exhibit differentiated evolution characteristics with curing age, which directly affects the long-term shear stability of materials. The primary failure modes of the composites include fiber pull-out and fiber bridging, which can be attributed to the relatively small average particle size of total mine tailings. The proposed fiber-reinforced composite for mining applications can enrich the types of support materials for metal mine roadways and facilitate the development of surrounding rock stability control technology.