Abstract: Starting with an investigation of the drawbacks of existing concentration measuring approaches for magnetic ink, a novel concentration measuring method and system based on the concept of electromagnetic induction was proposed, and the calibration method of the system was studied and analyzed. The results show that the technique can realize accurate and rapid determination of magnetic powder content in magnetic suspension, and the measurement repeatability of system is good, and it can be used in engineering practice. Finally, the differences and causes of the calibration curve of different fluorescent magnetic powder materials were analyzed, and the solution was put forward.