An installation for pre-assembling the turbine stators of a turbine each formed of several juxtaposed sectors, includes: an input carriage for conveying sectors intended to form the turbine stators. Each sector includes side faces provided with slots and being associated with a given turbine stator; an output carriage having various trays, each associated with a turbine stator; an automated device for inserting sealing pads configured to interact with a sector conveyed by an automated convey pallet, comprising a robot arm for inserting sealing pads into the slots in a side face of the sector; and another robot arm for gripping a sector equipped with pads from a pallet and depositing it on the tray associated with the turbine stator to pre-assemble the turbine stator.