A plane cable fault locator based on time domain reflection includes a high speed pulse generating and transmitting circuit, a high speed pulse acquisition and treatment circuit, an impedance matching circuit, a signal storing and treating system, a communication interface, a power supply system, an information display system, an external connection computer system and an information input system. The plane cable fault locator based on time domain reflection adopts a low pressure high speed pulse reflection method to diagnose the types of plane cable short circuit and open circuit and other faults through observing fault point reflection pulse waveform according to a time domain reflection principle, and subsequently calibrates the position of a fault point by measuring the time difference of transmitted pulse and the reflected pulse of the fault point. As the rising edge time of the pulse transmitted by the locator is short and reaches nanosecond level, the locating precision is high. In addition, the locator can accurately calibrate the plane cable fault position so as to avoid taking a plurality of clamping plates apart when looking for faults in plane cable maintenance, thus improving the maintenance efficiency of planes and ensuring the flying safety of planes.