A microdisk-resonator add-drop temporal integrator, composed of a long-range hybrid plasmonic waveguide, with graphene as the central layer, is proposed for the first time, to the best of our knowledge. The integrator benefits from a considerable integration time of ∼5.55ps, which is about 11 times longer than our previously proposed plasmonic integrator, and also is fairly comparable with the integration time of a microring-based integrator with a ring radius of 47.5 µm. Based on 3D-finite-difference time-domain simulations, the integrator, with a significantly compact footprint of ∼4µm×3µm, shows the FWHM of 53 GHz. The presented graphene-based temporal integrator, with a highly miniaturized footprint and satisfactory integration time, may find applications in ultrafast plasmonic-based signal processing systems.