A kind of chalcogenide glass midinfrared dual-core photonic crystal fiber has been proposed in this paper. The coupling characteristic of this fiber has been studied by multipole method using the basic theory of coupling. It is found that the birefringence of dual-core PCF with pitch 5.4 μm, air-hole radius 1.35 μm and air-filling fraction 0.5 is 0.551×10-2 at normalized frequency λ/Λ = 2.04 μm. At normalized frequency λ/Λ = 0.93 μm, coupling lengths are 145.32 μm and 154.68 μm for x-polarized mode and y-polarized mode, respectively. The band extended to midinfrared. This dual-core photonic crystal fiber with coupling length and high polarization is useful for manufacturing midinfrared band optical fiber coupler.