A novel double air hole multi-core dual-mode large-mode-area optical fiber is proposed. The characteristics of mode field distribution, effective area of fundamental mode, and bending loss are analyzed. And the effects of all structure parameters on the effective refractive index and effective area are discussed. This structure makes TE01 and TM01 mode cut off, and it is of dual-mode transmission in the fiber. Besides, this structure can increase the effective area. The effective area of fundamental mode is approximately 1044 μm2. It is even able to achieve single-mode operation by adjusting the structure parameters. The fabrication of the structure is simple, and design is flexible. Therefore, it is suitable for the high-speed and large-capacity passive fibers as well as for active fibers. The effective area can reach or even exceed 3512 μm2 by adjusting the structure parameters, in order to satisfy the practical demands of large-capacity high-power fiber transmission in the optical communications.