Abstract: In order to explore the precursory characteristics of strong tremor,based on the microseism and electromagnetic radiation technologies,tthe law of tremor appearance in the first section of the working face,which locates in the north No.17 seam of the third mining area of the Junde Coal Mine is studied,the strong tremor characteristics during the mining period of the working face is obtained.When the daily vibration energy and the number of events are maintained at a high level,it represents the symptom of strong tremor appearance and the pulse of electromagnetic radiation.Both impulse value and intensity are very small,indicating that there will be a large energy release soon,which is also the precursory signal of strong tremor.