The invention discloses a garbage gasification coupling coal-fired power plant power generating apparatus and power generating process. The power generating apparatus comprises a garbage primary treatment unit, a garbage pyrolysis gasification unit, a garbage flying ash melting unit and a coal-fired power plant power generating unit. The power generating process comprises the following steps: pyrolysing and gasifying garbage by utilizing a circulating fluidized bed gasification furnace to generate high-temperature fuel gas, sending the high-temperature fuel gas into a coal-fired boiler, burning and coupling the high-temperature fuel gas to generate power, melting the garbage flying ash in a melting chamber, chilling, and using as a construction material or directly burying. The fuel gas obtained by pyrolysing and gasifying the garbage and high-temperature smoke generated by the molten slag are coupled with the coal-fired power station to generate the power, and the power generating efficiency is high; by adding dechloridation co-solvent in a gasification furnace, the emission amount of dioxin is far less than the international standard; and the garbage flying ash of the invention is molten and then chilled to form glassy slag which can be used as the construction material or can be directly buried, so that the floor occupation area is small, no heavy metal is leached, and safety and environmental protection can be realized.