Abstract: Permanent magnetic transmission technology has quick response speed, simple structure, low failure rate, low maintenance cost, high reliability, long life and other advantages.Due to special environmental condition limit in coal mine and the requirements of related safety standards, permanent magnetic transmission devic need to be modified. The article studies the working principle of permanent magnetic transmission devic, analysizes its compliance of coal mine explosion-proof parameters and its effect for coal mine safety production, which makes the application of permanent magnetic transmission technology more safety in coal mine.