The effects of pyrolytic oil-based drilling cuttings (OBDC)/ orange bark (OB) biochar on passivation and remediation of Cu (Ⅱ) and Pb (Ⅱ) contaminated soil and its effects on soil microorganisms were investigated. The pyrolytic OBDC/OB biochar (OBDCs-OB) was added to Cu (Ⅱ) and Pb (Ⅱ) contaminated soil for 83 days of passivation and remediation experiments were reported. The results show that OBDCs-OB has functional groups such as —OH and —COOH, mineral compositions such as carbonate rocks and clay minerals, and porous structure, which can be used as adsorbent. Compared with the blank soil, after adding OBDCs-OB, the cation exchange capacity (CEC) of soil increased by 18.29 cmol/kg, and the pH was maintained at about 6.80. Acid-soluble Cu (Ⅱ) and Pb (Ⅱ) concentrations in soil decreased by 18.21% and 20.07%, respectively, and changed to reducible state. The potential leaching toxicity of Cu and Pb decreased by 52.8% and 92.8%, respectively, which effectively passivated Cu (Ⅱ) and Pb (Ⅱ). The maximum value of soil microbial population was 8.6×1010 cfu/g, and the maximum value of soil dehydrogenase and urease activities was 127.10 μgTPE/(g·6 h) and 167.10 mgNH3-N/(kg·24 h), which increased the diversity and richness of soil microbial community and promoted the growth of soil microbial community. In conclusion, OBDCs-OB can deactivate heavy metals in the remediation of heavy metal contaminated soil, promote the growth of soil microorganisms, and increase the diversity and richness of microbial community, which has practical application potential and provides basis for OBDC resource utilization.