The invention discloses a novel template-free anti-corrosion ultra-high performance concrete (UHPC)-normal concrete (NC) bearing platform and a construction method thereof. The combined bearing platform comprises a prefabricated UHPC protective layer and a cast-in-place core common concrete part; the prefabricated UHPC protective layer specifically comprises a prefabricated UHPC protective layer and a prefabricated UHPC protective layer, a UHPC bearing platform bottom plate, a bottom plate reserved groove, a bottom plate reserved round hole, a bottom plate reserved pile hole, a prefabricated UHPC side plate I, a prefabricated UHPC side plate II, a side plate reserved through hole, a prefabricated UHPC bearing platform top plate, a top plate reserved groove, a top plate reserved through round hole, a top plate reserved column hole and full-thread screws; the prefabricated UHPC top plate, the side plates and the bottom plate are connected through the full-thread screws, and bar-plantingglue is injected; coarse-aggregate-free UHPC is cast in place at the top plate for hole sealing; before the top plate is covered, a bearing platform reinforcement cage is placed in a space formed by the prefabricated UHPC protective layer, and the normal concrete is cast in place. The prefabricated UHPC protective layer not only can prevent the bearing platform from being corroded, but also can play a role of a template, so that the cost is reduced, and the on-site construction workload is reduced.