The present invention provides a sampling device for an ultrasonic transducer, comprising: a sampling module, suitable for collecting current signals, that is, sampling signals, outputted by the ultrasonic transducer； a differential amplification module, suitable for performing differential amplification process on the sampling signals, outputting first alternating current signals； a phase filter module, suitable for acquiring, according to driving signals of the ultrasonic transducer, voltage phase signals of the ultrasonic transducer； a phase rectification and extraction module, suitable to perform, according to the voltage phase signals of the ultrasonic transducer, phase decomposition on the first alternating current signals, obtaining two current signals having same and opposite phase as the voltage phase, and summing the two current signals to obtain phase rectification signals； and a current extraction module, suitable for extracting effective current in the phase rectification signals and output the effective current. The present invention further provides an ultrasonic surgical system comprising the sampling device above, and a tuning method for the ultrasonic transducer. The present invention improves measurement accuracy of effective current, and can accurately monitor state of the ultrasonic transducer according to the effective current.La présente invention concerne un dispositif d'échantillonnage pour un transducteur ultrasonore, le dispositif comprenant : un module d'échantillonnage adapté à collecter des signaux de courant, c'est-à-dire des signaux d'échantillonnage, émis par le transducteur ultrasonore ； un module d'amplification différentielle adapté à effectuer un procédé d'amplification différentielle sur les signaux d'échantillonnage et à délivrer des premiers signaux de courant alternatif ； un module de filtrage de phase adapté à acquérir, en fonction des signaux de commande du transducteur ultrasonore, des signaux de phase de tension du transd
