Some embodiments of the present disclosure provide a transducer including a high intensity focused ultrasound (HIFU) transducer including a HIFU emitting unit configured to emit a treatment ultrasound and an imaging transducer arranged in proximity of the HIFU transducer and configured to emit an imaging ultrasound. With a parabolic shape, the HIFU emitting unit has an inner circumferential surface formed with a plurality of recesses for extinguishing the treatment ultrasound or the imaging ultrasound, back-reflected to the HIFU emitting unit.
