The invention relates to an SCR denitrification device for dedusting the smoke of a cement kiln at a high temperature. The device is characterized by comprising an electric dust catcher (2) communicated with a cement kiln pre-heater (1), wherein the output end of the electric dust catcher (2) is communicated with a mixer (3) through a pipeline; the mixer (3) is provided with a compression air inlet (4), a reducing agent inlet (5) and a reducing agent spray gun (31); the output end of the mixer (3) is connected with an SCR reactor (61) through the pipeline; a catalyst (62) is arranged in the SCR reactor (61); and a booster fan (8) for discharging the purified smoke into a downstream apparatus is arranged at the output end of the SCR reactor (61). The device has the benefits that the high-temperature smoke is dedusted by the high-temperature electric dust catcher, thereby effectively avoiding flay ash abrading, blocking and inactivating the SCR catalyst; and CaO particles in the smoke of the cement kiln are removed, thereby avoiding the catalyst micropore blocking caused by CaO particles and the catalyst blocking caused by CaSO4 generated by a reaction between the CaO particles and SO3.