A signal processing device and a signal processing method. The signal processing device includes a receiver, a memristor array and a classifier. The receiver is configured to receive a first signal. The memristor array includes a plurality of memristor units, each of the plurality of memristor units includes a memristor, and the memristor array is configured to apply the first signal that has been received to at least one memristor unit of the plurality of memristor units and output a second signal based on a memristor resistance value distribution of the memristor array. The classifier is configured to classify the second signal outputted from the memristor array to obtain a type of the first signal.