A steering power system for an electric vehicle, comprising: a steering motor (M); a steering motor controller , connected with the steering motor (M) and configured to control the steering motor (M), wherein the steering motor controller comprises a direct current bus capacitor (C); a high voltage power battery , configured to output a first voltage; a low voltage storage battery , configured to output a second voltage lower than the first voltage; a buck DC-DC converter , connected with the high voltage power battery and the low voltage storage battery respectively, and configured to convert the first voltage outputted from the high voltage power battery into the second voltage for being supplied to the low voltage storage battery , when a high voltage system of the electric vehicle is working, wherein input terminals of the buck DC-DC converter are connected with the high voltage power battery in parallel via a first DC-DC connector (K1), output terminals of the buck DC-DC converter are connected with the low voltage storage battery in parallel; and a boost DC-DC converter , connected with the low voltage storage battery and the steering motor controller respectively, and configured to convert the second voltage outputted from the low voltage storage battery into the first voltage, wherein input terminals of the boost DC-DC converter are connected with the low voltage storage battery in parallel, output terminals of the boost DC-DC converter are connected with the direct current bus capacitor (C) in parallel, and the high voltage power battery is connected with the direct current bus capacitor (C) in parallel, and wherein when the high voltage system of the electric vehicle has an abnormal power failure, the boost DC-DC convertor converts the second voltage outputted from the low voltage storage battery into the first voltage for being supplied to the steering motor controller . a steering motor (M); a steering motor controller , connected with the steering motor (M) and configured to control the steering motor (M), wherein the steering motor controller comprises a direct current bus capacitor (C); a high voltage power battery , configured to output a first voltage; a low voltage storage battery , configured to output a second voltage lower than the first voltage; a buck DC-DC converter , connected with the high voltage power battery and the low voltage storage battery respectively, and configured to convert the first voltage outputted from the high voltage power battery into the second voltage for being supplied to the low voltage storage battery , when a high voltage system of the electric vehicle is working, wherein input terminals of the buck DC-DC converter are connected with the high voltage power battery in parallel via a first DC-DC connector (K1), output terminals of the buck DC-DC converter are connected with the low voltage storage battery in parallel; and a boost DC-DC converter , connected with the low voltage storage battery and the steering motor controller respectively, and configured to convert the second voltage outputted from the low voltage storage battery into the first voltage, wherein input terminals of the boost DC-DC converter are connected with the low voltage storage battery in parallel, output terminals of the boost DC-DC converter are connected with the direct current bus capacitor (C) in parallel, and the high voltage power battery is connected with the direct current bus capacitor (C) in parallel, and wherein when the high voltage system of the electric vehicle has an abnormal power failure, the boost DC-DC convertor converts the second voltage outputted from the low voltage storage battery into the first voltage for being supplied to the steering motor controller . <EOS>