Aiming at the simulation requirements of radar target and environmental characteristcs, the passive scattering elements are defined and classified. The essential characteristics of the controllable technology of electromagnetic scattering characteristics are analyzed. The commonly used controllable methods are introduced, and the current situation of the controllable methods of electromagnetic scattering characteristics at home and abroad is elaborated from five aspects: shape control technology, material control technology, radar absorbing material technology, frequency selective surface technology and plasma technology. According to the engineering requirement, the problems and challenges faced in this field are analyzed, and the development trend is briefly viewed.