Heavy metal pollution in soil poses a serious threat to ecological environment security and human health. In the remediation of soil contaminated with heavy metals, microbial remediation has advantages such as cleanliness, efficiency, low cost, and ecological friendliness, but it is difficult to achieve long-term stable remediation. The synergistic remediation of soil contaminated with heavy metal by biochar and bacteria was studied to improve the efficiency of sustainable remediation. Based on bibliometric analysis and the background of the remediation for soil contaminated with heavy metal, the stabilization characteristics of heavy metals in soil by bacteria and biochar, as well as the interaction between biochar and bacteria were summarized. The limitations of remediation of soil contaminated with heavy metal by single biochar or bacteria were analyzed and the advantages of synergistic remediation technology of bacteria and biochar were emphasized. The effective remediation of soil contaminated with heavy metal by bacteria and biochar mainly through important mechanisms such as ion exchange, fixation, oxidation-reduction, and migration was described, and the great application value for synergism of bacteria and biochar in the remediation of soil contaminated with heavy metal was revealed. Bibliometric studies showed that the synergistic remediation of soil contaminated with heavy metal by biochar and bacteria has received widespread attention. At present, it is believed that the synergistic effect of biochar and bacteria can effectively improve the physicochemical properties of soil and the efficiency of soil remediation, as well as promote plant growth and phytoremediation processes. Biochar has a dual effect on bacteria, promoting their growth and potentially causing toxicity to them; Bacteria can alter the physicochemical properties of biochar, enhancing the heavy metal fixation performance of biochar. During the process of bacteria cooperating with biochar for the remediation of soil contaminated with heavy metal, biochar dominates adsorption and fixation, while bacteria play functions such as activation and detoxification. Optimizing the combination of bacteria and biochar and developing synergistic technologies between the mixed bacteria and multiple types of biochar are important issues that urgently need to be addressed for sustainable remediation of soil contaminated with heavy metal. Further revealing the coupling effect and long-term mechanism of bacteria and biochar on soil contaminated with heavy metal, avoiding potential ecological and health risks in biochar production and application, and developing new high-efficiency bacteria-biochar complexes are the challenges facing the application field of sustainable remediation for soil contaminated with heavy metal through the synergistic effect of bacteria and biochar.