China has a large number of informal landfills that are operating under excessive pressure, which has led to a number of environmental issues that need to be resolved immediately. High heavy metal content landfill leachate can easily contaminate the water near the landfill, and the aged waste produced by landfill mining expansion also contains excessive amounts of heavy metals such as Cd, Pb, Zn, and Cr (Ⅲ), which can easily result in secondary pollution during resource use. Therefore, the issue of heavy metal pollution in landfills requires urgent attention. The efficacy of Microbial Induced Carbonate Precipitation (MICP) technology to immobilize heavy metals has recently been thoroughly investigated. Sporosarcina pasteurii has drawn interest due to its high expression of urease and excellent environmental adaptability. However, in related investigations, the principal remediation materials are contaminated solutions and regular soil, which are visibly distinct from aged refuse in terms of the causes of contamination and chemical make-up. As a result, this study conducted experiments on the bioremediation of heavy metal contaminated solutions and aged refuse, investigated the viability of heavy metal bioremediation by S. pasteurii, and examined the changes in the heavy metal fraction before and after bioremediation as well as the remediation mechanism. The findings indicate that Cd, Pb, Zn, and Cr (Ⅲ) remediation rates from the solutions by S. pasteurii could be as high as 95%, 84%, 5% and 98%, respectively. Additionally, exchangeable Cd, Pb, and Zn remediation rates from aged refuse could reach 74%, 84%, and 62%, respectively, while the exchangeable Cr(Ⅲ) concentration before remediation is virtually 0. After the bioremediation, the amount of residue-bound and iron-manganese oxide-bound heavy metals in the aged refuse increased whereas the amount of exchangeable and carbonate-bound heavy metals dropped. Meanwhile, the MICP process,s calcium carbonate precipitation and the Fe and Al content of the aged refuse both support the conversion of heavy metals into a more stable fraction.