The invention belongs to the technical field of ultrasonic emission and particularly relates to a same-phase dense-arrangement array type ultrasonic emitting unit capable of emitting high-strength and high-directivity ultrasonic waves. The same-phase dense-arrangement array type ultrasonic emitting unit is composed of a same-phase ultrasonic transducer array and a printed circuit board. According to the requirement, ultrasonic transducers of different physical performances and geometric sizes are designed, arrayed in a dense-arrangement manner and correspondingly inserted into the printed circuit board matched with the dense-arrangement array. An ultrasonic signal subjected to power amplification is input into the same-phase dense-arrangement array type ultrasonic emitting unit, and the same-phase dense-arrangement array type ultrasonic emitting unit is made to emit out the high-strength and high-directivity ultrasonic waves. The same-phase dense-arrangement array type ultrasonic emitting unit capable of emitting the high-strength and high-directivity ultrasonic waves can be used for directional spreading of the sonic waves and can also be used for the fields of ultrasonic suspension, distance measurement, remote control, imaging, emulsification, sterilization, chemical reaction promoting, biological research performing and the like.