Wideband full-polarization measurement for radar target is of important application in the research fields of radar imaging and target recognition. Based on orthogonal frequency division and full-polarization instantaneous measuring method, a new waveform vector was designed to get full-polarization information simultaneously under wideband condition. Firstly, the models of emitting and receiving signals were given, and full-polarization datum in frequency could be gathered, and then target full-polarization range profiles were obtained after IDFT. Finally, the validity of this measuring method was verified by simulation, using simulated datum and real measured datum.