The invention discloses a disc koji-making device. The disc koji-making device comprises a central column (10), a koji tray (40) and a rotary bearing (30), wherein the rotary bearing (30) comprises a lower support ring (31), multiple rolling bodies (33) and an upper support ring (32), the lower support ring and the upper support ring sleeve the central column, the lower support ring is fixedly connected with the central column, and the upper support ring can be rotationally supported on the lower support ring through multiple rolling bodies and is fixedly connected with the koji tray. The disc koji-making device is characterized in that the rotary bearing further comprises a coaxial retaining structure used for keeping the upper support ring and the lower support ring in a coaxial state. The disc koji-making device can realize at least one of technical effects of simplifying the production process of the disc koji-making device, reducing the number of parts, lowering the assembling difficulty, decreasing the production and maintenance costs and the like.