Aiming at the difficulty of locating cable open circuit faults, the paper proposes a location method of the improved adaptive genetic algorithm combined with the BP neural network. The improved adaptive genetic algorithm is used to optimize the selection of the weight threshold of the BP neural network, and the predicted location results are compared with the same type of algorithms. The results show that the combined method of the improved adaptive genetic algorithm and BP neural network has a better effect on the location of cable fault distance. Finally, an example of faulty cables in a phased array radar cabinet is used to verify the feasibility of the proposed method in locating the cable open circuit fault.