The mechanical–chemical-modified fly ash (FA-MC) and mechanical–chemical-brominated fly ash (FA-MC-Br) were prepared by omnidirectional planetary ball mill, and impregnated–brominated fly ash (FA-I-Br) was also prepared using the same mass ratio of fly ash/NH4Br as a comparison. The mercury-removal efficiency of raw fly ash (FA), FA-MC, FA-MC-Br, and FA-I-Br was evaluated in a fixed-bed reactor. The physical and chemical properties of the four samples were investigated by the Brunauer–Emmet–Teller, scanning electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, and mercury temperature-programmed desorption analysis. The results showed that the mercury-removal efficiency of the four samples followed the order of FA-MC-Br > FA-I-Br > FA-MC > FA, the value of which was 67, 30.98, 26.12, and 17.96%, respectively. The mercury-removal performance of the four samples was mainly reflected in the oxidation (>90%), while the adsorption only accounted for a small proportion (<10%). The mechanical–...