The present disclosure provides a method for testing a USB cable applied in an electronic device. The electronic device includes a battery charged by a charger via the USB cable. The method can include determining at least two different values of charging currents. The method can further include generating a first control signal according to the determined values of charging currents. Sending the first control signal to the charger via the USB cable, to inform the charger to respectively charge the battery by charging currents with the determined values. Detecting values of at least two voltages output to the battery. Comparing a calculated variation degree between the detected values of voltages with a preset variation degree. Generating a first type of message according to a compared result between the calculated variation degree and the preset variation degree.