Due to the shortcomings of fault location system of distribution networks and the problems of genetic algorithm that it is prone to premature convergence and its convergence speed is slow, this paper proposes a fuzzy adaptive simulated annealing genetic algorithm (FASAGA) by integrating fuzzy inference and adaptive simulated annealing genetic algorithm. This algorithm improves fault tolerance of the fitness function, adopts the adaptive strategy and the optimal individual reserve strategy in genetic selection, calculates fuzzy adaptive crossover operator and fuzzy adaptive mutation operator by combining fuzzy inference and adaptive strategy, and adopts simulated annealing algorithm to improve convergence speed and local search ability. The accuracy, effectiveness and tolerant performance of this algorithm applied to the fault location of distribution networks are verified by simulation results.