Many landfills in China have undergone "extended service", resulting in many new environmental problems. High heavy metal content landfill leachate can easily cause pollution to the surrounding water bodies of landfills. The aged refuse generated by the expansion of landfill mining also exhibits excessive heavy metals such as Cd, Pb, Zn, and Cr (III), which can easily cause secondary pollution during resource utilization. Therefore, the problem of heavy metal pollution in landfill sites urgently needs to be addressed. In recent years, the ability of MICP technology to immobilize heavy metals has been extensively explored and sporosarcina pasteurii has attracted attention due to its strong environmental adaptability and high expression of urease. However, the remediation objects in related studies are mainly contaminated solutions and ordinary soil, which are obviously different from aged refuse in terms of pollution causes and chemical composition. In view of this, this research carried out experiments on bioremediation of heavy metal contaminated solutions and aged refuse, explored the bioremediation feasibility of heavy metals by s. pasteurii, and analyzed the changes in the fraction of heavy metals before and after bioremediation and the remediation mechanism. The results show that removal rates of Cd, Pb, Zn, and Cr (III) in the solutions by s. pasteurii could reach 95%, 84%, 5%, and 98%, respectively.Also the removal rates of exchangeable Cd, Pb,and Zn in aged refuse could reach 74%, 84%, and 62% , respectively , and the content of exchangeable Cr (III) before remediation is almost 0. The content of exchangeable and carbonate-bound heavy metals in the aged refuse is reduced, and the content of the iron-manganese oxide-bound state and residues are increased after bioremediation. Meanwhile, The Fe content in the aged refuse and the calcium carbonate precipitation produced by the MICP process jointly promote the conversion of heavy metals to a more stable fraction.