The unique electromagnetic properties of left-handed materials have received much attention due to their applications in microwave devices, radar antenna and electromagnetic stealth and so on. However, the double side etching of dielectric substrate for most traditional left-handed materials will lead to the complexity of manufacture, narrow left-handed bandwidth and higher loss. In order to overcome the shortages of traditional left-handed materials, a new broadband and low-loss left-handed material with multi-opening cross shape structure is presented in this paper. The structure is fabricated on a single side of a dielectric substrate by integrating an electric resonator with a magnetic resonator to form a left-handed unit. Through theoretical analysis, software simulation and effective electromagnetic parameters extraction, the results show that the structure has a double negative characteristics (ε μ <0) in the 12.7-21.1 GHz range, which is basically in the Ku band. The absolute bandwidth of left-handed character is up to 8.4 GHz and the loss of unit cell is less than 0.3 dB. The structure realizes a wider left-handed bandwidth with smaller cell size and lower loss than the conventional left-handed materials, and it provides an important reference for the application and design of the broadband and low-loss microwave left-handed materials.