In the process of microbial solidification and stabilization of heavy metal contaminated soil, the rapid reaction rate and the inhibition of high concentration of salt ions on bacterial activity are the key problems that hinder the substitution of single stirring process for com-plex multi-round grouting process. The solidification and stabilization tests of zinc-contaminated silt were carried out by using sin-gle-stage microbial stirring method. In the tests, low-solubility gypsum (calcium sulfate dihydrate) was used as calcium source for microbial induced mineralization reaction, and the calcium salt content and the zinc pollution concentration were adopted as the control variables to investigate the changes of soil strength, zinc ion leaching concentration and chemical forms. The results show that the unconfined compressive strength of solidified and stabilized zinc-contaminated silt is inversely proportional to the concentration of zinc pollution. When the content of calcium salt is 20.2%, the solidification strength of 500mg/kg zinc-contaminated silt is 77.3% higher than that of untreated zinc-contaminated silt. Meanwhile, the concentration of zinc ion leaching is 87.3% lower that of untreated zinc-contaminated silt. The exchangeable zinc content in solidified/stabilized soil decreased with the increase of calcium salt content, and the migration of heavy metal zinc in soil decreased. Scanning electron microscopy, Infrared spectroscopy and X-ray diffraction analysis show that calcium carbonate, zinc carbonate and basic zinc carbonate are formed in the solidified and stabilized zinc-contaminated silt, and carbonate crystals aggregate to form porous clusters. A single stirring microbial mineralization treatment based on gypsum calcium source can significantly improve the strength of zinc-contaminated silt, effectively stabilize zinc ions in the polluted powder, and reduce its mobility. This technique has potential application in solidifying/stabilizing zinc-contaminated silty soil site.