A device (1) for preventing and detecting the falling of an object or of a person on a line (2) of a railway station having a platform (3). The device (1) includes at least one detection device (7) having at least one emitter (8) of a beam (10) and a sensor (9) able to detect the beam (10), and a detection calculator (13) for processing the signals obtained from the sensors (9) and able to communicate safely with at least one signaling system (16a, 16b, 16c) of the railway station, barriers (4) able to be arranged on the platform (3) to prevent falls of the object or of the person, the barriers (4) delimiting between door opening areas (5), a detection device (7) being arranged in each of the door opening areas (5) to detect a fall on the line (2) of the railway station.