Abstract: According to the very complicated electromagnetic wave transmission environment in the mine roadway,the paper analyzed electromagnetic wave transmiss ion environment features in a mine circular type roadway,provided an approximate solution method of the wave mode equation for the circular roadway,obtained an approxi mate expression of each wave mode attenuation constant in the mine circular roadway and had a numerical simulation on the calculation results. The analog simulation res ults showed that the cut- off frequency of electromagnetic wave transmission in the mine roadway only depended on the cross section radial of the circular roadway and ha d no any relationship with other factors. With the cross section radial of circular roadway increased,no matter TE wave mode or TM wave mode,the cut- off frequency all wo uld be reduced and would be favorable to the electromagnetic wave transmission. A TE01 wave mode with high frequency would be suitable to transmit in the mine circular roadway.