Typical soil solidifiers, such as ordinary Portland cement, have a limited solidification effect when used as solidifiers, and they can cause significant environmental pollution during the manufacturing phase. Therefore, a relatively green and environmentally friendly solution based on magnesium sulfate cement (BMSC) is explored as a solidifying agent for solidifying the soil. The present paper undergoes a systematic compaction experiment, an unconfined compressive strength test, and an unconsolidated undrained triaxial shear parameters test of BMSC solidified soil with different magnesium oxide (MgO) contents when BMSC was used as the soil stabiliser and the physical properties of BMSC solidified soil were analysed by the techniques ofX-ray diffraction (XRD), scanning electron microscopy-energy spectrometry (SEM-EDS), XAn analysis was conducted on the mechanical properties and microstructure of BMSC solidified loess. When the molar ratio is determined, the maximum dry density increases with the increasing magnesium oxide doping. The results indicate that the compressive strength of BMSC solidified loess increases with the increase in the MgO content. Specifically, the compressive strength of the 6 % BMSC solidified loess specimen increased by 528 % compared with that of the pure loess specimen. Moreover, the maximum deviation stress increased by 236.54 %, while the cohesion and internal friction angle increased by 221.89 % and 44.27 %, respectively. The XRD and-ray computed tomography (X-CT), and mercury intrusion porosimetry (MIP). SEM/EDS analyses revealed a great number of 517 (5Mg(OH)2-MgSO4-7H2O) whiskers crisscrossing between the soil particles, which made the microstructure of the BMSC solidified loess specimen denser. The MIP results showed that the macropores and porosity reduction decreased from 43.30 % of the pure loess to 37.01 % in the 6 % BMSC solidified soil specimen. Similarly, the X-CT results revealed a higher pore density and larger porosity in pure loess.