Electrolytic manganese residue (EMR) occupies a lot of land resources and may result in potential heavy metal pollution. In order to solve these problems, electrolytic manganese residue-based cementitious materials, initial electrolytic manganese residue and medium-coarse sand were employed to fabricate the filling material self-cemented with electrolytic manganese residue used for mine backfilling. The fluidity, compressive strength and leaching toxicity of hydration slurry of the filled composite were tested to evaluate the performances of the synthetic material, and the microstructure was characterized with X-ray diffraction and scanning electron microscopy. The results showed that the fluidity of the filling material slurry reached 200 mm, meeting the needs of technical requirements of filling; the compressive strength of the solidified body of the filling material could reach 1.5 MPa or more after curing for 28 days, meeting the conditions of the filling body strength for mining site; the leaching toxicity of the filling material significantly reduced with the main heavy metals including Mn and Co fully solidified and stabilized, meeting the national groundwater quality standard. The results of XRD and SEM analysis make it clear that the hydrated calcium silicate, ettringite and other crystals generated by the hydration of the filling material are the main reasons why the strength of the solidified body was stable and the heavy metals were solidified. All these findings indicated that this method could effectively solidify/stabilize electrolytic manganese residue and reduce the risk of environmental pollution.