Radar technology can be applied to small body exploration missions for subsurface detection and global interior structuredetection. In this paper, the current applications both at home and abroad are introduced, and the different application scenes of monostatic radar and bistatic radar are described and the characteristics ofmonostatic radar loaded on the orbiter and the rover are presented. Through analyzing of potential material and structure of small bodies and studying the working principles of monostaticand bistaticradars, the available radar mode for a small body with potential structure is proposed. For a layered small body, which is always in a relatively large size, the monostatic radar can be applied for subsurface detection. While for a rubble pile small body, the bistatic radar can be used to obtain its permittivity and image the global interior structure using transmitted waves over global observation. The effectiveness of the bistatic radar forinterior structure detection of a rubble pile asteroid is verified through numerical simulation.