The purpose of complex resistivity measurement of coal in laboratory is to provide reliable data of complex resistivity for further field application. The measurement accuracy of coal complex resistivity is affected by many factors, and electrode plate is one of the most important factors. The thickness and the size of electrode plate will affect the result of coal complex resistivity measurement, so the change of electrode plate is of great significance to the accuracy of measurement parameters. In this paper, the complex resistivity of the electrode material with three different thicknesses is measured by using the copper material with better conductivity as the electrode plate. The influence of the thickness of electrode plate on the induced polarization effect is analyzed. The influence of different sizes of electrode plates(diameter of 1 cm, 2 cm, 3 cm, 4 cm and 5 cm) on the measurement of the complex resistivity of coal is tested, and the Cole-Cole model is used for data fitting. The results show that 1) the polarization effect of the electrode plate itself and the bonding degree between the electrode plate and the end face of the coal sample are the main factors affecting the measurement error of the complex resistivity of the coal sample, and the error of the conductive copper paper is the smallest among the three electrode materials. 2) For the same coal sample, the change of the area of the electrode plate only has a great influence on the amplitude of the complex resistivity, and the influence of the area on the induced polarization of the coal sample can be ignored.