Abstract: 3D braided fibers were treated through the composite surface treatment process，  and the 3D hybrid epoxy composites reinforced by carbon fiber (CF) and UHMWPE fiber were prepared using the resin transfer molding (RTM) process. The mechanical properties and the hybrid effect were analyzed. The results show that，  with the decrease of the hybrid ratio of UHMWPE fiber/CF，  the flexural and longitudinal compressive performances of the 3D UHMWPE/CF/ER composites are improved，  and their longitudinal shear strength and impact toughness decrease. The fracture mechanism of the 3D UHMWPE/CF/ER hybrid composites is determined by the properties of the two fibers and their hybrid ratio. The mechanical properties of the hybrid composites can be effectively adjusted by the hybrid ratio of the two fibers.