The simultaneous improvement of mechanical and functional properties of Ti alloys is of considerable significance for their diverse applications and service life. Incorporating graphene with Ti is hoping to realize that, however, it is challenging to achieve the improvement because of the poor chemical stability of carbon/Ti systems. This challenge becomes particularly significant when using high carbon-content reinforcements, as the reinforcement agglomeration is considered to adversely affect composite performances. In this work, an efficient powder metallurgy method was developed to fabricate titanium matrix composites reinforced by a high content of graphene nanosheets (GNSs). Quasi-continuous GNSs were arranged in a 3D network and were surrounded by in-situ TiC. The results revealed that the load-transfer and solid-solution strengthening factors contributed to the high mechanical strength of the composites. Moreover, the GNS networks conduced to the improvement of thermal conduction, reduced the total weight, and enhanced the anti-wear performance of the composites via self-lubrication. Furthermore, the proposed approach can be applied to other carbon/metal composites for achieving significant improvements in their performance.