Coal fire-caused mercury emission has become the fourth major pollutant after dust, SO2 and NOx, which has attracted widespread concerns. This paper introduces the existing mercury-removal techniques used for coal-fired units, and the application of the US mercury control process, and highlights the features and application of two major technologies, including the activated carbon injection (ACI) and the simultaneous multi-pollutant removal technology. In the end, relevant suggestions are proposed on process route selection of mercury control for coal-fired power plants.