Endoscopic ultrasound (EUS) plays a vital role in the development of novel treatment and diagnostic methods of gastrointestinal diseases. The ultrasonic transducer is an essential component, whose working frequency determines the quality of ultrasonic images. In general, the higher the working frequency, the easier it is to obtain high-quality images. Nevertheless, increasing the frequency often leads to a decrease in detection depth, which limits the imaging range and is unfavorable in clinical use.