The present invention is applicable to the field of electrics and provides an integrated circuit (IC) and a standby controlling method thereof. The IC comprises a reset device, a standby control device, a functional device and a power supply control device. The functional device at least comprises a functional unit that does not operate in a standby mode. The power supply control device is configured to supply power to the functional device, the standby control device and the reset device. The standby control device is configured to control the power supply control device to control a power supply voltage of the functional unit to be within a preset range below a normal operating voltage when a standby status signal is detected, and restore the power supply voltage into the normal operating voltage when a wake-up signal is detected; and the reset device is configured to reset the functional device when the system standby status signal is detected and release the resetting of the functional device when the wake-up signal is detected. The IC of the present invention reduces the time required by the IC to wake up from the standby mode while ensuring that the whole functional device has low static power consumption.