The invention discloses a support device for a tobacco dryer, which comprises a plurality of support units arranged between the roller and the transmission ring of the tobacco dryer. Each support unit comprises a first roller fixing seat, a second roller fixing seat, a transmission ring fixing seat, a transmission ring pressing plate, a first slanted pressing plate and a second slanted plate, wherein the first roller fixing seat and the second roller fixing seat are fixed on the outer wall of the roller; the transmission ring fixing seat is arranged on the inner wall of the transmission ring; the transmission ring pressing plate is fixedly connected on the transmission ring fixing seat; the first slanted pressing plate is fixedly connected between the first roller fixing seat and the transmission ring pressing plate; and the second slanted pressing plate is fixedly connected between the second roller fixing seat and the transmission ring pressing plate and is symmetrical with the first slanted pressing plate. The support device has uniform stress, and can effectively prevent cracking of the welding seam of the fixing seat due to fatigue damage, thereby lowering the disorderly closedown rate of the tobacco dryer, reducing the amount of dry head and tails of the tobacco shreds and ensuring the overall quality of the dried tobacco shreds.