The researches on network area denial sub-munitions have just begun in our country. The location technology was one of the key technologies in network area denial sub-munitions. This article described the principles of the sub-munitions using ultrasound location technology, and a network area denial sub-munitions ultrasound system had been designed. Also, the hardware configuration, the software design process and experimental data processing methods were presented. The experiment based on those researches shows that the deviation is less than 1 meter when the system detects in the range of 8 meter to 22 meter, and this system can implement the function of orientation roughly.