According to the theory of traditional Maxwell-Wagner interface polarization, the metal micro/nano particles have no obvious electrorotation behavior under the alternating current electric field. However, we find the opposite experimental results. In this paper, electrorotation experiments are carried out, and the basic mechanism of gold-coated SU-8 microrods is presented. Therefore the electrorotation characteristics of gold-coated microrod at low frequency are analysed by considering the surface electric double layer at the microrod-electrolyte interface. Specifically, first we establish an approximate ellipsoid model in the electric field, analyze the polarization mechanism of metal particles under the action of solid-liquid interface electric double layer, and then calculate the electrorotation torque and present an electrorotation angular speed formula of the gold-coated microrod. Secondly, electrorotation experiments of gold-coated SU-8 microrods suspended in electrolytes with different conductivities are presented in a frequency range of 100 Hz to 30 MHz. Finally, the experimental results are discussed, and compared with the theoretical analysis, showing the experimental results are in good agreement with theoretical analyses by considering the friction between the microrods and substrate.