The invention discloses a cement quantitative sub-packaging device. The sub-packaging device comprises a rotating disc, wherein multiple sub-packaging holes are formed in the rotating disc; metering cylinders are arranged above the sub-packaging holes, and the volume of inner cavities formed by the metering cylinders and the sub-packaging holes is equal to the volume of cup bodies used for plasterpackaging; the lower part of the rotating disc is provided with a sub-packaging mechanism, a cup conveying rail and a cup pushing mechanism for pushing the cup to move along the cup conveying rail; the sub-packaging mechanism comprises a feeding plate, wherein the feeding plate is provided with a feeding groove and a feeding port enabling the feeding groove to be connected with an external feeding pipe; the device drives the metering cylinders to rotate to the upper side the feeding groove through the rotating disc, and the cement in the feeding groove is filled in the metering cylinders dueto pressure; and further, when the measuring cylinders moves to the upper side of the cup conveying rail, the pressing plate of a filling mechanism is used for discharging the cement in the metering cylinders out of the cup body on the cup conveying rail. According to the cement quantitative sub-packaging device, automation of cement quantitative sub-packaging is realized, and accuracy of the quantitative sub-packaging is improved.