The invention discloses a combine harvester threshing cylinder assembly. The combine harvester threshing cylinder assembly comprises a front assembly, a main shaft, a front main shaft connecting plate, a middle main shaft connecting plate, a rear main shaft connecting plate, installation holes, connecting rods, grain beating teeth, installation sheets, front installation seats, rear installation seats and bolts. The front assembly is fixedly installed on the front main shaft connecting plate, the front end of the main shaft is fixedly installed in the installation hole of the front assembly, the rear end of the main shaft is fixedly installed in the center hole of the rear main shaft connecting plate, the connecting rods are radially provided with the plurality of grain beating teeth, the front installation seats are fixedly installed in clamping grooves at the front ends of the connecting rods, the rear installation seats are fixedly installed in camping grooves at the rear ends of the connecting rods, the connecting rods are fixedly provided with the installation sheets, the front installation seats are installed at the front main shaft connecting plate, the rear installation seats are installed at the rear main shaft connecting plate, and the middle main shaft connecting plate is installed on the installation sheets of the connecting rods. The combine harvester threshing cylinder assembly is simple in structure, convenient to install and maintain and low in cost; and the combine harvester threshing cylinder assembly is provided with the six connecting rods, the disengagement effect is good, and the disengagement efficiency is high.