Abstract: The paper pointed out that realization of unattended operation of fixed workplace of coal mine underground and limited worker operation of fully mechanized mining face and fully mechanized caving face needs to establish control system of coal mine with remote control function, video monitoring system, mine-used scheduling and communication system, mobile communication system, etc. It proposed that information transmission system of mine should meet requirements of wide transmission bandwidth, wired transmission mode combined with wireless mode, strong anti-fault ability, long transmission distance, high reliability, standardization, perfect safety performance, etc. It proposed double-tree redundancy structures of double cables in two tunnels separately, double cables in a tunnel and single cable based on analying advantages and disadvantages of structures of wired transmission networks of coal mine underground including star, ring, tree and bus mode, and considered ideal wired transmission network of coal mine underground should be the double-tree redundancy structure of double cables in two tunnels separately and double cables in a tunnel. It also put forward a view that wired broadband information transmission of coal mine underground should use mine-used Ethernet based on passive optical network or active optical network, and proposed main performances and technique requirements of the two Ethernets.