In order to reduce the complexity of software and hardware design in multi-channel eddy current testing, a multi-channel real-time eddy current testing system based on lock-in amplifier technology and self-balancing technology is designed. The system uses graphical programming language platform (LabVIEW), Myrio1900 data acquisition control card and lock-in amplifier as key components. The lock-in amplifier adopts the lock-in technology to detect the amplitude and phase of the weak eddy current signal. The Myrio1900 card outputs multiple analog switch control signals and collects the amplitude component of the weak eddy current signal. The LabVIEW platform uses self-balancing technology to eliminate the imbalance of the bridge itself. The detection system realizes the real-time and reliable display of the amplitude and XY components of the 6-channel eddy current signal. Experimental results show that the designed system has a detection width of 56.00 mm at one time, and can detect artificial grooves with a covering layer of 2.90 mm. The artificial grooves have a width of 1.00 mm, a depth of 1.00 mm and a length of 50.00 mm. The system design process described in the article can be used as a reference for equipment developers and can also be used for educational purposes.

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