In this paper, Cu-Nb microcomposite (8 #) with 7 cores reinforced by graphene coated with niobium powder and reinforced by pure niobium powder (9#) with 7 cores were successfully prepared by accumulative drawing and bundling process.The breakage phenomenon of wire in plastic processing has been significantly improved after the optimization of heat treatment process, especially the wire (8 #) reinforced by graphene coated with niobium powder,which have a regular uniform distribution of the core and a good coordination.Through the analysis of the microstructure, mechanical properties and electrical properties of two kinds of wire with different sizes (Φ2.49mm, Φ2.29mm, Φ2.02mm, Φ1.84mm), the results show that the mechanical properties of Cu-Nb wire reinforced by graphene coated with niobium powder increased only tens of MPa that compared with reinforced by pure niobium powder, however,the conductivity of the Cu-Nb wire increased obviously, which reached 10 IACS%.Finally, the plastic deformation mechanism of two kinds of wires were analyzed.