Selecting an appropriate conductor joint method is essential by considered conducting wire safety performance. The Analytical Hierarchy Process (AHP) method is usually used for solving multi-criteria decision-making problems. However, the traditional AHP method is incapable of handling the uncertainty and vagueness involving the mapping of one's preference to an exact number or ratio. In this paper, Fuzzy Analytic Hierarchy Process (FAHP) is improved based on decision-making theory which can automatic define the evaluation indexes weight. The FAHP is applied to evaluate the best adequate conductor joint method resulted in less temperature up rate, lower maximum temperature and less electric resistance up ratio. The result obtained by FAHP is showed that different material conducting wire need select different joint method in order to decrease the probability of electrical joint fire occurrence.