Abstract: LCC-HVDC transmission system has numbers applications in world. But the inherent technical characteristics of LCC-HVDC transmission system may cause some problems, such as the failure of commutation of converter station, unable to supply power to weak AC system. Hybrid DC transmission technology has the advantages of both two kinds of HVDC technology. It has the high flexibility control method and low cost, and has a good prospect in the energy convergence of renewable energy, asynchronous grid interconnection and long-distance transmission. In this paper, the DC field wiring scheme of the VSC-HVDC converter in hybrid HVDC system is proposed and optimized according to its characteristics. The performance of the system is improved and the investment cost is saved. And it has wide application prospect. for the reconstruction of LCC-HVDC converter station to VSC-HVDC converter station.