A dual-band plasmon induced transparency (DBPIT) metamaterial based on monolayer graphene in terahertz regime is designed and studied numerically. We demonstrated that both the resonance frequency and transmission amplitude of the structure can be independently tuned by manipulating the Fermi level of graphene via gate voltage. The terahertz transmission of the DBPIT can be well reproduced with a classical three-oscillator model. Furthermore, the transmission amplitude can be additionally enhanced due to the improved mode coupling originated from the magnetic near field enhancement enabled by the Diabolo-like structure. This work may open up a new avenue for designing multiple-band functional devices.