Plane wave expansion method has systematically studied the complete Photonic Band Gap(PBG)of copper-coin-shaped triangular lattice Photonic Crystal(PC).The results demonstrate that the copper-coin-shaped scatterers is a combination of the air hole type and dielectric rod type of PCs,which in favor of obtain a wider complete PBG width.The width of the complete PBG has certain stability to deviation of doped material and the air hole radius caused by the preparation process.The two types of dielectric of which the PC are composed must have sufficiently large dielectric constant ratio to get the complete bandgap.The copper-coin-shaped triangular lattice PC begins to appear complete bandgap when the ε=11.8.By grouping optimization of parameters,the widest complete PBG of Δωa /2πc is 0.136 1 with Δω/ωmid of 33.55% when ε is 22.75,R is 0.483 μm,d is 0.195 μm,φ is 90° and G is 1.3.