In order to study the abnormal transmission phenomenon of C-type curved metal arrays with circular holes, the transmission spectrum and electric field distribution are obtained through experiments. The process of generating and transmitting optical lattices is analyzed for the C-type curved metal circular hole arrays. It is found that C-type curved metal circular hole arrays based on waveguide and tunneling modes exhibit anomalous transmission mechanisms, with tunneling mode evolving from waveguide mode and maximum transmission decreasing with increasing bending degree. There are three main reasons for this: first, the reflectivity of the C-type curved metal circular hole array is at a relatively high level at the maximum transmittance; second, the efficiency of electric field coupling in the metal circular hole array is reduced due to the waist variation of the light field with Gaussian like distribution in the optical lattice above the array and the deviation between the centers of the light field and circular hole; finally, the significant bending effect of C-type circular hole leads to large electric field transmission losses.