Abstract: In order to solve the problem of corrosion testing of the pipeline with the coatings, a type of the non-contact guided wave testing system based on the magnetostrictive effect, is developed. The system comprises sensors, main processor and software. Laboratory testing and filed application validated the effectiveness and practicality of the system. Due to the non-contact detection method, the system can be employed to detect not only the low temperature and the high temperature coated pipelines but also other coated slightness components such as stay cables, suspenders and so on.