［Purposes ］ To solve the problems of low activity and poor mineralization effect of conventional microbially induced calcite precipitation （MICP） strains in salt -alkali environments，mineralizing bacterial resources suitable for the high salt -alkali environment of the South China Sea must be explored.［Methods］ An indigenous salt -alkali -tolerant ureolytic bacterium，Savagea faecisuis，was screened from mangrove sea mud in the South China Sea by techniques such as enrichment culture and purification separation，and then it was domesticated.The mineralization ability of the strain was evaluated by measuring its growth curve，urease activity，and tolerance under different salt -alkali conditions.A sand column solidification test was conducted using this strain to verify the solidification effect under salt -alkali conditions.［Results］ The results indicate that the urease activity of the strain varies with the changes in the growth cycle and environmental salinity and alkalinity，and its maximum value reaches 7.11 mmol/（L·min）；the mineralization deposition amount is 1.43 g，and the product is rhombohedral calcite crystals.The strain shows strong tolerance to salt -alkali stress，with a maximum tolerated mass concentration of NaCl ［β（NaCl） ］ of 0.09 g/mL and a maximum tolerated pH of 10.5.Through the domestication method of stepwise stress，the environmental survival ability and urease activity stability of the strain are enhanced.The strain can still has stable activity even under the conditions of β（NaCl）=0.09 g/mL and pH= 10.5.The results of the sand column solidification test show that under the conditions of β（NaCl）=0.05 g/mL and pH= 9.5，the internal soil particles of the solidified sand column are effectively cemented by the deposited calcium carbonate，and the unconfined compressive strength of the solidified sand column reaches about 400 kPa.［Conclusions ］ The screened and domesticated Savagea faecisuis possesses excellent salt -alkali tolerance and mineralization ability，which can provide an effective microbial source for the construction of islands and reefs in the South China Sea and the ecological restoration of saline soil.