Abstract: This paper introduces the cable parameters and measurement methods, and summarizes test methods of the cable used by intrinsically safety electrical apparatus in domestic coal mine inspection organizations. The paper analyzes the problems in the application of system authentication in theory through a practical example, and summarizes the method of parameter authentication commonly used in IECEx. In order to solve explosion protection of the cable for long distance power supply, the paper proposes the schemes to improve the allowable length of the cable.