An automatic infusion device and a control method therefor. Said method comprises the steps of: when a first infusion bottle (51) is used for the infusion of a patient, a gravity sensor (7) on the first infusion bottle (51) detecting a gravity signal of medicinal liquid in the first infusion bottle (51) determining, according to the gravity signal, whether the medicinal liquid in the first infusion bottle (51) has run out when the medicinal liquid in the first infusion bottle (51) runs out, a controlling switch (22) automatically switching to a drainage tube (6) of a second infusion bottle (52) so as to use the medicinal liquid in the second infusion bottle (52) for the infusion of the patient when the medicinal liquid in the second infusion bottle (52) runs out, turning off an infusion mode of an automatic infusion device and activating a cleaning mode the controlling switch (22) introducing cleaning liquid from a cleaning bottle (53) to clean the automatic infusion device, and discharging waste liquid generated after the cleaning from an outlet (25) of an automatic bottle switching device (2) to an external waste liquid bottle. The automatic infusion device and the control method can automatically perform a switch among the infusion bottles (51, 52) so as to automatically change the medicinal liquid for the patient and automatically clean the infusion device, realizing a safe and sanitary infusion process.Linvention concerne un dispositif de perfusion automatique et son procédé de commande, le procédé comprenant les étapes suivantes : quand un premier flacon de perfusion (51) est utilisé pour perfuser un patient, détection à laide dun capteur de gravité (7) situé sur ledit premier flacon de perfusion (51) dun signal de gravité du liquide à usage médical contenu dans ledit premier flacon de perfusion (51) détermination, en fonction du signal de gravité, que le liquide à usage médical contenu dans le premier flacon de perfusion (51) a fini de sécouler quand le liqui
