In this paper, the uniaxial compressive strength and electrochemical impedance response of red mud- coal metakaolin with different Na/Al at a conservation age of 28 days were tested and analyzed in series. Based on the characteristics of ion diffusion within the geopolymer, a basic equivalent circuit model was established, and the equivalent circuit was fitted and analyzed using ZSimDemo3.30d software. The relationship between the parameters of each circuit element and Na/Al was analyzed. The results reveal that the compressive strength of the red mud-coal metakaolin geopolymer increases first and then decreases with increasing Na/Al. The results of the electrochemical impedance spectroscopy test that all the Nyquist diagrams show a flat capacitive reactance arc in the high frequency region and an insignificant diffusion curve in the low frequency region; the equivalent circuit model is R(Q(RW)).As Na/Al increases, both the total resistance of the geopolymer system and the electric double layer capacitance in the aluminosilicate gel increased first and then decreased, while the charge transfer resistance decreased. By using electrochemical impedance spectroscopy, this study reveals the changes in the compressive strength of red mud-coal kaolin geopolymers with Na/Al, proves the feasibility of electrochemical impedance spectroscopy applying to the geopolymer testing and analysis process, the electrochemical impedance spectroscopy provides a new idea and method for non-destructive testing of geopolymers.