Metal surface plasmon has many novel optical properties and important applications, and it is also a research hotspot. In this paper, a crescent cross (CC) nanostructure composed of a crescent and a cross is studied by the finite element method. New plasmon magnetic mode and multiple Fano resonance can be induced by breaking structure symmetry through changing structure parameters. Meanwhile, by changing the angle between the two rods symmetrically, the figure of merit (FOM) can reach 61. Our structure has important applications in the fields of multi-wavelength sensor, ultra-sensitive biosensor, surface enhanced spectroscopy, and slow light transmission.