The invention provides a connecting method for endless rolled intermediate slabs. The method comprises the following steps: aligning the head and tail end portions of front and back intermediate slabs; rubbing the tail portion end surface of the front intermediate slab and the head portion end surface of the back intermediate slab; applying a forward force to the back intermediate slab in the rubbing period; and when the temperature of the connecting end surface of the front and back intermediate slabs is raised to a viscoplastic state, connecting the head of the back intermediate slab forward together with the tail portion of the front intermediate slab under the action of an upsetting force. The method provided by the invention is high in connecting strength, fast in connecting speed and low in energy consumption and is suitable for connecting slabs made from different materials.