With urbanization progressing, the continuous generation of solid waste from production and daily life makes their recycling and reuse increasingly important. In this paper, magnesium oxysulfate cementitious materials, widely used in construction and environmental engineering for their light weight, high strength, good fire resistance, and low energy consumption, have been prepared in two forms: one with added solid waste and one without. canning electron microscope, quasi static compression, and split Hopkinson Pressure Bar experiments are conducted on the two kinds of magnesium oxysulfate cement (MOSC) to investigate and compare their microscopic configuration and quasi-static and dynamic mechanical properties. The experiments show that due to the addition of solid waste, the compressive strength of MOSC increased significantly at various strain rates, especially when the strain rate was 0.001 s⁻¹, where its strength nearly doubled. It can be seen that the MOSC with solid waste exhibited finer particle sizes from the microstructure of the two types of MOSC, which reduced the porosity of the concrete and further enhanced its compactness, leading to greater compressive strength. Both types of MOSC displayed obvious strain rate effects. Comparing their dynamic increase factor (DIF), it was found that the addition of solid waste weakened the influence of strain rate on MOSC. When the strain rate was low, the MOSC with solid waste exhibited less damage, indicating increased toughness. However, as the strain rate increased, the fracture levels of both types of MOSC became more similar. The MOSC with solid waste showed significant advantages at low strain rates, such as high strength and toughness. This study demonstrates the feasibility and application prospects of using solid waste in magnesium oxysulfate cementitious materials.