The purpose of complex resistivity measurement of coal in laboratory is intended to provide reliable data of complex resistivity for further field application. There are many factors that affect the measurement accuracy of coal complex resistivity, among which electrode plate is one of the most important factors. The selection of electrode material, thickness and 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 three kinds of electrode materials with different thickness is measured by using the copper material with better conductivity as the electrode plate. The influence of the thickness of the electrode plate on the induced polarization effect is analyzed. The influence of five kinds of electrode plates with diameter of 1cm, 2cm, 3cm, 4cm and 5cm on the measurement of the complex resistivity of coal is tested. The Cole-Cole model is used for data fitting. The conclusions are as follows: (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 resistance 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 resistance, and the influence on the induced polarization of the coal sample can be ignored. In this paper, the importance of electrode material and contact area is considered to improve the accuracy of the measurement of the complex resistivity of coal samples in the laboratory, which lays a foundation for the research of the experimental method of the complex resistivity of coal and the field application of the complex resistivity method.