The invention relates to a method for synchronizing interconnected critical devices comprising servers and clients, each critical device being connected to another critical device by a virtual link, each termination of which is associated with a minimum and a maximum value of transmission time for a data packet, the method, implemented periodically, comprising: the reception of a message at a reception instant, said message comprising at least one time reference determined by a transmitter server,for each message received, the estimation of the current time of the transmitter server on the basis of: the time reference, a value of the internal clock of the current critical device at the current instant and at the reception instant, the minimum value and the maximum value of transmission time of the virtual link between the transmitter server and the current critical device.