The soil solidification technology based on microbial- or enzyme-induced carbonate precipitation process has the characteristics of high strength and environmental friendliness. However, it has limitations such as low treatment efficiency and time-consuming. This paper studies the treatment method, effect and mechanism of another biological soil solidification technology based on the urease-enhanced magnesia carbonization process. Comparisons were made against pure magnesia carbonation, enzyme-induced calcium carbonate precipitation (EICP) and Portland cement. The results show that when the urease-enhanced magnesia carbonization treatment method is used, a higher strength (0.92 MPa) can be obtained after one treatment, and the strength of the sample is significantly higher than that of the samples treated with pure magnesia (0.30 MPa), EICP (0.28 MPa) or Portland cement (0.69 MPa). The preparation method of the urease-enhanced magnesia carbonization treatment sample also has great influence on the strength. Compared with the one-phase injection method, the strength of the sample treated by the pre-mixed method was 3 times higher. In addition, the strength of the urease-enhanced magnesia carbonization treatment sample was further improved by about 70%, and the highest strength reached 1.30 MPa, with the addition of small amount of non-fat milk powder. Through microstructural and mineralogical analysis, it was found that after urease-enhanced magnesia carbonization treatment, the solidified materials filled the pores between the sand particles, cemented the sand particles together, and formed a stable spatial structure. It could also be seen that soil treatment by urease-enhanced magnesia carbonization led to higher hydrated magnesium carbonates content, and lower brucite content.