Abstract: In response to the problem of difficult in recycling and using bulk industrial solid waste, various goals of solid waste reduction, harmless treatment, and resource utilization have been achieved. An environmentally friendly permeable concrete paving bricks (PCB) were prepared using the harmless treatment slag of electrolytic manganese residue, red mud, and coal fly ash from three typical types of bulk solid wastes of gypsum, alkaline, and silicoalumina from enterprises in southwestern China. The effects of water washing and slag content on the mechanical properties and leaching toxicity of the prepared PCB was studied, and the phase composition and microstructure of the optimal performance PCB were analyzed by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The results show that: (1) As the amount of harmless slag and water washed harmless slag increases, the splitting tensile strength and linear failure load of road bricks change significantly, showing an overall decreasing trend. When the amount of harmless slag added is 6% and water washed harmless slag added is 14%, after 28 days of curing, the splitting tensile strength of the prepared bricks is 4.09 MPa and 3.46 MPa, respectively, reaching the f_ts4.0 and f_ts3.0 levels specified in Permeable Paving Bricks & Permeable Paving Flags (GB/T 25993-2010). (2) The leaching toxicity of heavy metals and NH₄⁺-N in road bricks is lower than the relevant requirements in the Technical Specification for Coprocessing of Solid Waste in Cement Kiln (GB 30760-2014). The main supporting substances of pavement bricks are calcite, quartz, and ettringite. The research shows that the harmless slag obtained by the collaborative treatment of electrolytic manganese residue, red mud, and coal fly ash can replace some raw materials to prepare permeable concrete paving bricks, meet the relevant standards of mechanical properties and leaching toxicity, and effectively promote the reduction and resource utilization of solid waste. It is recommended to further conduct environmental risk tests on the bricks in actual application scenarios to provide clearer support for the comprehensive utilization technology development of electrolytic manganese slag, red mud, and coal fly ash.