Donor-acceptor-type semiconductor polymer IPDT composed of isoindigo, propylene dioxythiophene and thiophene unit was used to constructe an organic electronic device with a configuration of Al/IPDT/ITO. It was found that the device had obvious memory resistance characteristics with ON/OFF voltages of 8 V/-7.5 V and a high-low resistance ratio over 10 ². The effect of laser irradiation under different wavelengths on the memory resistance performances of the device was studied. The results show that a laser with 632-nm wavelength and 3-mW power strongly affects the memory resistance performances. After irradiation for 60 s, the current trend of the device is reversed. The ON/OFF voltagess are reduced to -2.2 V/1.3 V and the high-low resistance ratio is increased to 10 ⁴. The current is decreased by an order of magnitude, the fluctuation of the current-voltage curve is decreased, and the power consumption of the device is effectively reduced. The number of stability cycle tests is increased from 2000 before laser irradiation to 3500, which improves the accuracy and stability of data reading.