Abstract: Purpose As a major energy producer and consumer, the construction and application of a multi-energy complementary system (MES) in oilfields is a key path to achieving their energy conservation, consumption reduction, and emission reduction goals. This study focused on the energy supply and demand characteristics of a joint station in Daqing Oilfield and constructed a MES architecture to improve energy efficiency, reduce system operating costs, and promote low-carbon transformation. Method By coupling traditional energy supply units with renewable energy generation units, an innovative water electrolysis hydrogen production and storage synergistic optimization model was introduced to synergistically address the uncertainty of renewable energy output and the random fluctuations of multiple load types. A system planning model integrating a tiered carbon trading mechanism and a demand response mechanism was further established, and simulation analysis was conducted based on four typical configuration scenarios. Results and Conclusion Simulation results show that compared with the traditional energy supply model, the constructed system significantly improves energy efficiency (by over 30%) and reduces operating costs by 41.2%. The introduction of a tiered carbon pricing mechanism reduces total system costs by 16.05% and carbon emissions by 6.74%. The addition of a demand response mechanism can achieve an additional 1.3% carbon emission reduction. This study can provide a technical solution with engineering application value for the low-carbon transformation of oilfield energy systems, and confirms that the multi-energy complementary system has important potential in achieving coordinated optimization of economy and environmental protection.