The utility model discloses a hand -held type permanent magnetism switch coil operation circuit detector, including pilot lamp LED1, diode D1, current -limiting resistor R1, operation power source and operating coil interface, link to each other with pilot lamp LED1 behind operation power source's the anodal current -limiting resistor of connection, pilot lamp LED1 connects diode D1's positive pole, and diode D1's negative pole links to each other with the operating coil interface, and operation power source's negative pole links to each other with the operating coil interface, and the measuring current in the detector is less than 10mA. The utility model discloses it is simply easy -to -use, need not the outside cooperation that has a power failure, need not to provide alone the power, there is not complicated software to support, engineering practicability is strong. Utilize operation circuit's operating power itself, whether normal, need not waste a large amount of manpowers if externally detecting permanent magnetism switch coil operation circuit under circuit the normal power supply's the circumstances, do not influence production efficiency, has solved the maintenance method influence production of present permanent magnetism switch, the problem that wastes time and energy.