The invention discloses a cable fault rapid lossless positioning device based on chaos synchronization. The cable fault rapid lossless positioning device comprises a microwave chaos signal source circuit, a power divider, an amplifier, a T-shaped connector, a low-noise amplifier, a chaos synchronization circuit, a rapid correlation measurement unit, a signal processing unit and a power supply, wherein a signal generated by the microwave chaotic circuit is used as a test signal, the chaotic signal is divided into two paths that one path of reference signal and one path of test signal input to a to-be-tested cable through the T-shaped connector, an echo signal reflected back from a cable fault position drives another microwave chaoscircuit used for chaossynchronization, and a synchronization signal output by the microwave chaoscircuit and the reference signal are subjected to fault position delay time measurement through the rapid correlation measurement unit so as to detect the position parameter of the circuit fault point. According to the invention, the correlation between the echo signal and the reference signal is improved, the workload complexity of back-end data processing is reduced, the data processing speed is improved, and the overall performance is improved.