PURPOSE: To provide a control system of extrusion molding capable of automatically replacing a filled feed palette with an empty feed palette even when a molding host computer produces no palette replacing request by the trouble of the molding host computer.

CONSTITUTION: In a control system of extrusion molding controlling extrusion systems 10A, 10B, a crane device 30 and an automatic storehouse 40 to introduce the molded product extruded from an extrusion molding machine 11 into the automatic storehouse 40, when the amt. of cut molded products reaches a preset amt., controllers 2A, 2B generate full state signals showing a full state. A feed host computer 3 judges that a molding host computer 1 is deficient when receives only the full state signals from the controllers 2A, 2B to issue a command replacing a full feed palette with an empty feed palette to a controller 4.