Abstract: In order to solve the problem of stockpiling and resource waste of polyaluminum chloride slags in the chemical industry, this paper uses polyaluminum chloride slags as raw materials to prepare sintered bricks with polyaluminum chloride slags at high temperature, studies the influence of different molding conditions and sintering conditions on sintered bricks with polyaluminum chloride slags, and uses X-ray diffraction (XRD) and scanning electron microscopy (SEM) to characterize the phase composition of sintered bricks with polyaluminum chloride slags in the sintering process, and analyzes its evolution process. The results show that the optimum molding pressure, molding moisture, heating mode, heating rate and sintering temperature are 27.5 MPa, 17.5%, direct sintering, 8 ℃/min and 1 100 ℃ respectively. At this condition, the compressive strength of sintered brick is 33.5 MPa, the water absorption rate is 18.63%, the bulk density is 1.73 g/cm³, and the linear shrinkage rate is 6.6%, meeting the requirements of MU30 grade in the national standard 《Fired common bricks》(GB/T 5101—2017). The research shows that the main phase of the sintered brick is quartz, quartz and other fluxes form liquid phase to fill the pores, which makes the structure more compact. The above results can be used for references in preparing sintered bricks from polyaluminum chloride slags.