The invention discloses an active carbon carbonizing device, comprising a cylinder body, a base bracket, and a sieve box arranged at the inner part of the cylinder body, a collecting box and a vibrator; the collecting box is located beneath the sieve box, and the base bracket is arranged at the bottom part of the cylinder body, and the outer wall of the sieve box is provided with a diagonal slag guiding ring slice; the slag guiding ring slice is perpendicular to the outer wall of the sieve box, and the highest place of the slag guiding ring slice makes contact with the opening face of the sieve box, and the lowest place of the slag guiding ring slice makes contact with the bottom part of the outer wall of the sieve box; the contact place between the lowest place of the slag guiding ring slice and the inner part of the cylinder body is provided with a slag discharging pipeline; the slag discharging pipeline crosses through the cylinder body, a spring is arranged between the outer wall of the sieve box and the inner wall of the cylinder body; the bottom face of the sieve box is provided with a guide pipe, and the guide pipe crosses through the outer wall of the cylinder body; the vibrator is arranged at the bottom part of the cylinder body. The active carbon carbonizing device can carry out one-time sieving by the sieve box with different apertures while collect active carbon with multiple grain diameters; meanwhile, the active carbon with unqualified grain diameter can be recycled.