<p>Lead (Pb) and zinc (Zn) are widely recognized as common environmental contaminants, contributing to soil degradation and posing risks to environmental health. Combining functional carbon-based materials with microorganisms has been considered as an effective and environmentally friendly strategy for remediating Pb/Zn-contaminated soil. However, there is still a lack of understanding the connection between heavy metal immobilization and plant responses, which hampers practical applications. Here, a 90-day pot experiment was conducted to investigate the integrated effects of biochar (WS700) and microorganisms including inorganic phosphate-solubilizing bacteria (IPSB) and sulfate reducing bacteria (SRB) on Pb and Zn synchronous immobilization and the physiological responses of Brassica rapa var. chinensis (Brassica). Compared with CK, bacteria-loaded biochar treatment declined the exchangeable Pb and Zn fraction by 94.69%–98.37% and 94.55%–99.52%, while increasing the residual state Pb and Zn by 75.50%–208.58% and 96.71%–110.85%, respectively. Three amendments enhanced Brassica growth by improving total chlorophyll content and superoxide dismutase (SOD) and peroxidase (POD) activities. The bacteria-loaded biochar treatment effectively regulated stomatal conductance and reduced intercellular CO₂ concentration. Moreover, compared with CK, three amendments reduced MDA content by 28.84%, 28.30% and 41.60%, respectively, under the high concentration of Pb and Zn. The findings demonstrated the significant role of bacterial-biochar consortia in immobilizing Pb and Zn and mitigating Pb and Zn-induced stress in plants by regulating photosynthetic characteristics and antioxidant enzyme activities.</p>