Though comparison about performance and realizing method among several remote (communication) modes,the paper proposed a design scheme of remote monitoring and control system of coal(output) using Modem technology to realize remote communication,introduced design of hardware and(software) of communication between upper-computer,lower-computer and Modem.It also gave anti-(interference) measures of the system.The practical running showed that the system is stable and reliable in(working),and has certain use value.