Abstract: With the help of the expression of electric field produced by the vertical dipole in the full space of homogeneous electrical conduction,the relational expression between communication performance parameters and communication distance is derived.Again,according to the requirement in use (e.g.,the rated penetration distance,light weight and intrinsicaly safe explosion proof behavior and so on),various technical indexes of MT-1 are selected and established based on the relational expression.With respect to the actual bedded strata,when the electromagnetic wave is propagated along the coal (rock) bed,the communication distance might be larger than the design value due to the wavegiuide effect;when it propagated perpendicular to the rock bed,the communication destance could be enlarged using the prolongable receiving and emitting distance of horizontal dipole and low resistance emitting tap to increase the emitting electric current.This is proved by the industrial tests.