The invention relates to a bay loading safety device including: —an articulated platform (14), whose level can be altered to adapt to the differences in height between a lorry trailer (10) and a loading bay (12), —a door (15) for shutting off access from (13) a building (11) opening onto the bay (12), —a set of buffers (16a, 16b) fixed on either side of the platform (14) to provide protection for the bay (12) when the lorry trailer (10) comes alongside the said bay (12), characterized in that it comprises, —a sensor (31) able to monitor a zone (34), called the crush zone, —a sensor (36) able to determine the distance of the lorry (10) from the bay (12), —an obstacle (35) that can be retracted during the travel of a lorry (10), so as to prevent it from coming alongside the bay (12) depending on whether the whole or part of a fixed or mobile object (17) situated in that zone (34) is present and on the distance of the lorry (10) from the bay (12).
