The effects of single and hybrid reinforcement of carbon nanotubes (CNTs) and TiB2 particles on the microstructure, density, electrical conductivity, hardness and tensile strength of copper matrix composites were studied. Firstly, CNTs/Cu composites with brick structure were prepared by the combined preparation technology of ball milling, surface adsorption and hot-pressing sintering, which solved the problem of agglomeration of CNTs. The density and electrical conductivity of the sintered CNTs/Cu composites decreased with the increase of the CNTs content, while the tensile strength and elongation first increased and then decreased with the increase of the CNTs content. The comprehensive performance is the best when the content is 0.1 wt.%, and the density, electrical conductivity and tensile strength are 97.57%, 91.2 %IACS and 252 MPa respectively. Meanwhile, the density, electrical conductivity and tensile strength of the sintered 1 wt.% TiB2/Cu composite after ball milling are 97.61%, 58.3 %IACS and 436 MPa, respectively. Finally, hybrid reinforced (CNTs+TiB2)/Cu composites were prepared by introducing in situ TiB2 particles into CNTs/Cu composites with brick structure. Compared with single CNTs (or TiB2) reinforced copper matrix composites, the strength of CNTs and TiB2 hybrid reinforced composites is significantly improved. When 0.1 wt.% CNTs and 1 wt.% TiB2 were mixed, the composite density, electrical conductivity and tensile strength were 97.21%, 56.4 %IACS and 531 MPa, respectively. And the electrical conductivity decreases by 3.3%, while the tensile strength increases by 21.8% when compared with 1 wt.% TiB2/Cu. It is mainly attributed to the role of CNTs in carrying and transferring loads, and the pining dislocations of the dispersed TiB2 particles. The two strengthening mechanisms work together to significantly improve the tensile strength of (CNTs+TiB2)/Cu composites.