Abstract: The suspension guidance sensor fault of Shanghai Maglev Demonstration Line needs longer inspection and maintenance time, leading to higher cost as the result. To solve this problem, the signal processing board and coil flexible circuit board of the suspension guidance sensor are analyzed, the input signal produced by signal generator is transmitted to the test circuit board, then transmitted to the host system by the signal acquisition equipment to compare with the given signal. Then, according to the result of comparison, the fault dictionary is used to detect the fault area, thus the offline fault location system of guidance sensor could conduct inspection, realize fast location of sensor boards and improve the efficiency of maintenance. The research results have certain reference value for the maintenance work of high-speed maglev train.