We propose an ultra-wideband reconfigurable intelligent surface (RIS) based on a dual-wing grooved symmetric structure. In our design, the grooves on both sides of the unit cell can effectively extend the current path and significantly improve the unit's broadband characteristics. We couple it with a high-precision voltage-controlled driver circuit, and the proposed RIS can adjust the unit's electromagnetic response based on theoretical coding in real time, thus achieving precise electromagnetic wave control. Through our experiments, we find that the RIS achieves a 1 bit phase tuning range from 7.3 GHz to 13.9 GHz, with a relative bandwidth of 62.3%, covering the C, X, and Ku bands. Moreover, the RIS achieves radar cross section (RCS) reduction of more than 10 dB in the range of 7?14 GHz, and the reduction can reach up to 15 dB in most frequency bands, with the maximum reduction being 40 dB. Additionally, our experimental verification also confirms the RIS's capability to manipulate single beams, asymmetric dual beams, and multiple beams, which provides an important reference for the multi-band cooperative applications of RIS.