To obtain high precision electromagnetic calibration force, a calibration device used in micro-thrust measurement was designed. On the basis of studying the principle of electromagnetic force generation and calibration, the design requirements were introduced, and a calibration device based on the electronic analytical balance was designed, which could respectively adjust the horizontal distance, longitudinal distance and angle between the coil and magnet. Three physical quantities, the insensitive angle, the insensitive horizontal distance and the insensitive longitudinal distance were defined, which qualified the variation range of magnet and coil position corresponding to the output precision. The results show that the device can meet the design requirements, and can study the relationship between electromagnetic force and control current.