Abstract: Direct casting of smelting slag into glass-ceramic is considered to be an effective way to simultaneously utilize slag "slag" and "heat" and prepare high value-added materials, and research in this area has become a hot spot. In this paper, silico-manganese slag was used as the main raw material, and high-silicon, high-iron and chromium-containing modifiers such as silica, iron scale and ferrochromium slag were added respectively, and glass-ceramics were prepared by Petrurgic one-step method. The Petrurgic one-step method is a heat treatment method for preparing glass-ceramic by controlled crystallization during slag cooling. Through X-ray diffraction (XRD), differential thermal (DSC), scanning electron microscopy (SEM-EDS) and other tests and analyses, the influence of adding different modifiers on the mineral phase and properties of silicon-manganese slag glass-ceramics was discussed. In addition, the feasibility of the process of preparing glass-ceramics by on-line modification of silicon-manganese slag was further discussed through thermal balance calculation and analysis. The research shows that by cooling the modified slag to the crystallization temperature and annealing at 700 ℃, glass-ceramics that meet the performance requirements of natural granite can be obtained. The optimal sample of glass-ceramic prepared in this paper has a flexural resistance of 74.67 Mpa, a bulk density of 2.95 g/cm3, and a water absorption rate of 0.8%. Compared with the original silico-manganese slag, the crystallization performance of the modified slag has been significantly improved, and the iron scale and ferrochromium slag are more conducive to promoting the formation of granular or short rod-shaped pyroxene crystals with a particle size of 0.2~0.5 μm. These crystals are ordinary pyroxene (Ca(Mg,Fe,Al)(Si,Al)2O6) with solid solution of Mn and Fe ions, and pyroxene minerals such as CaMnSi2O6. The addition of modifiers changed the occurrence form of Mn ions in the silico-manganese slag. The Mn ions in the original slag mainly existed in the form of glass phase and manganese sulfide, and the manganese ions in the modified samples mainly occurred in the calcium-manganese pyroxene. Microcracks appeared in the samples after heat treatment, and the crystal density of pyroxene was larger than that of the glass matrix, and the volume shrinkage caused by its precipitation was one of the reasons for the formation of cracks. In the modification process of adding 10% silica and iron scale as modifiers respectively, the sensible heat of slag is greater than the melting endothermic heat of modifier, and no additional heat is needed in the modification process. When the ferrochromium slag is used as a modifier, the glass-ceramic can be prepared by the hot state mixing method of silicomanganese slag and ferrochromium slag.