Abstract: The correctness of the assembly position of spherical Luneberg-lens inside target missile is of paramount importance for the service performances of the target missile. A radar system for detection of target missile assembly in production line was designed to determin the correctness. The system is a continuous wave radar with 2.1GHz operating frequency, the combined use of this system with small anechoic chamber could achieve ten-fold difference or above of the output signal levels of radar system when spherical Luneberg-lens assembled forward and reverse inside target missle, thus the correctness or inaccuracy of assembly position could be detected. The system is characterized with easy operation, small volumn, high stability and low cost.