Abstract: Transmission model of very low frequency electromagnetic wave in mine-seam was built which was based on Maxwell equations, and transmission characteristics of very low frequency electromagnetic wave were researched when it transmitted on the interface of mine roadway and mine-seam, in mine-seam and on the interface of mine-seam and the ground. The conclusions are as following: when very low frequency electromagnetic wave transmits from mine roadway into mine-seam, it is approximately in the vertical incidence condition; when very low frequency electromagnetic wave transmits on the interface of mine-seam and the ground, total reflection will occur with a little critical angle, and a part of very low frequency electromagnetic wave cannot pass through the ground.