Abstract: This paper will use active frequency selective surface (AFSS) technology to design the electromagnetic structure of traditional Luneburg lens reflectors. AFSS Luneburg lens reflectors with switchable absorption/reflection will be used instead of metal reflectors to achieve an active Luneburg lens reflector that can adjust the reflection intensity/radar cross section (RCS) size of incident electromagnetic waves and switch the working state. The simulation results show that the designed new Luneburg lens reflector can achieve switchable absorption/reflection functions and adjustable monostatic RCS in the X-band, with a difference of about 8 dB. Finally, the physical processing and testing of the new Luneburg lens are carried out, and the measure results are in good agreement with the simulation results, achieving the switching of the working state of the Luneburg lens reflector within a certain frequency band and the adjustable RCS.