Ultra-small hand-held multi-channel ultrasonic system is a highly integrated system. This system has some advantages in nondestructive testing. Such as the size of the system is small, the detection with the system is convenient and so on. As for the design of this system, the 64-channel ultrasonic detection system in this paper is established. The consequence of ultrasonic detection system design is delay precision as 5 ns, sampling frequency as 100 MHz, bandwidth as 0. 02~ 25 MHz, volume as 40×70×90 mm 3 . According to the results of the delay precision experiment, Synchronous sampling experiment, defect detection experiment and guided wave imaging experiment, the design dose work. The system can expand to more channels for application to medical ultrasonic detection and the volume will not increase too much. Meanwhile, its size is relatively small among the same type instruments.