The invention provides a method for manufacturing a reinforced composite cable core, belonging to the field of high performance composites. The reinforced cable cores in the prior art have the following problems: (1) the thickness of the outer insulating layers is not uniform and even carbon fibers are locally exposed; (2) the transverse compressive strength is poor and the cores are easy to crack; and (3) the pultrusion speed is lower and is generally (0.2-0.6)m/min. The method is characterized by selecting epoxy resins (with epoxy value being 0.80-0.95mol/100g) with multi-functional groups,a modified anhydride curing agent, a modified imidazole accelerating agent, an inner release agent and a toughening agent, optimizing the resin mixing proportion, simultaneously introducing the fiberbraiding technology and braiding a sleeve layer outside the axially arranged inner core fiber bundles of the reinforced core to prepare the high performance reinforced composite cable core. The cablecore has the advantages of uniform insulating layer thickness, high transverse compressive strength, high production speed and high toughness.