The present disclosure provides a resistive-switching device capable of implementing multiary addition operation and a method for implementing multiary addition operation using the resistive-switching device. The resistive-switching device has a plurality of resistance values each corresponding to a respective data value stored by the resistive-switching device and ranging from a high resistance value to a low resistance value. The data value stored by the resistive-switching device is increased by ‘1’ successively with a series of set pulses having a same pulse width and a same voltage amplitude being applied thereto. The data value stored by the resistive-switching device is set to ‘0’ with a reset pulse being applied thereto, and meanwhile a data value stored by a higher-bit resistive-switching device is increased by ‘1’ with a set pulse being applied thereto. In this way, multiary addition operation is implemented.