The present disclosure provides a method and a system for testing an OLED display device. The method includes steps of: applying a testing signal to the to-be-tested OLED display device; acquiring a measured distribution image for a testing region of the OLED display device to which the testing signal is applied; comparing the measured distribution image with a corresponding calibrated distribution image so as to obtain a comparison result; determining whether or not there is a back plate abnormal point at the testing region in accordance with the comparison result; and when the comparison result indicates that there is a back plate abnormal point at the testing region, determining a position of the back plate abnormal point on the OLED display device.