▎ 摘　　要

We investigate the dephasing mechanisms induced by the charge noise and microwave heating effect acting on a graphene double quantum dot (DQD) capacitively coupled to a microwave resonator. The charge noise is obtained from DC transport current, and its contribution to dephasing is simultaneously determined by the amplitude response of the microwave resonator. A low-frequency 1/f-type noise is demonstrated to be the dominant factor of the dephasing of graphene DQD. Furthermore, when the applied microwave power is larger than -90 dBm, the dephasing rate of graphene DQD increases rapidly with the increase of microwave power, and fluctuates slightly with the applied microwave power smaller than -90 dBm. Our results can be applied to suppress the impeditive influence on the dephasing of graphene-based devices associated with microwave input in the perspective investigations.