In view of problem of single-point failure in hardware and software running environment of gas disaster early-warning system of coal mine, a gas disaster early-warning system based on hot-standby was proposed, and its hot-standby solution, hardware and software design and implementation were introduced. The system employs high-reliability hot-standby cluster for mutual backup and hot-standby solution based on RoseHA and shared disc array, greatly improves its reliability. The application result shows that availability of the gas disaster early-warning system based on hot-standby is greatly improved with longer mean time between failures and shorter mean time for fixing failure, compared with the early-warning system based on single server.