Aiming at the safety hazards in the implementation of the old pipe network reconstruction, pipe defect repair and new pipe network in the existing mine water supply and drainage system, this paper proposes a mine pipeline defect monitoring system design based on magnetic flux leakage nondestructive testing technology.Node design is applied in this system, the core technology of each node electronic module in conjunction with the other auxiliary tank section together, through the pipe wall corrosion, mechanical damage such as volume defects in the spillover of the lines of magnetic force signal and mileage wheel signal gathering, mixed encoding frame, store operations, such as the data of all nodes by wireless communication module after returned to the monitoring center decoding analysis, the analytical results show that each node of the system can accurately identify the defect location, and the positioning accuracy reaches 0.01 m.The real-time display effect of the system node and the defect location on the well meets the expectation.Meanwhile, based on the finite element simulation of pipeline defects, the effectiveness of the system is verified by simulation and comparison experiment.