The invention relates to a low-temperature smoke pre-dedusting device and method for a rotary hearth furnace. The low-temperature smoke pre-dedusting device comprises a smoke pipeline, a dedusting plate, a spiral dust sticking plate, a three-way connector and an access door. The dedusting plate is installed at the position, close to a smoke inlet, of the smoke pipeline, the spiral dust sticking plate is located in the smoke pipeline and located behind the dedusting plate, the three-way connector is installed at the outlet end of the smoke pipeline, one connector body of the three-way connector is connected with the smoke pipeline, one connector body is connected with an inlet of an external bag-type dust collector, and one connector body is connected with the access door.