A digital printing device, comprising a suction transport means (1). The suction transport means (1) comprises a transport belt (11) used for transporting a sheet material. At least one first suction box (14), which is used for sucking the sheet material on the transport belt (11) by means of negative pressure during transport, is provided in the space defined by the transport belt (11). Multiple first suction holes in communication with the first suction box (14) are provided on the transport belt (11). At least one side of the first suction box (14) is provided with a movable door (15) which moves in a direction perpendicular to the transport direction to make the first suction box (14) fit the sheet material to maintain a negative pressure state. Using the transport belt (11) during printing, the digital printing device avoids the problem of poor registration accuracy, and improves the printing effect.