The traditional quartz polarization-maintaining fiber cannot be used in the mid-infrared due to its limitation of phonon energy. Contrarily, the simulated birefringence of chalcogenide PCF is much higher. However, there is no experimental report about PCF because of its fabrication complexity. Therefore, this study proposes a novel "—" typed suspended-core chalcogenide fiber with a rectangle core, which is optimized based on the elliptical core fiber model. When the aspect ratio of the rectangular core is 3.6, the air hole radius is 28 μm, and the distance between the two air holes is 5.1 μm, the birefringence can reach up to 7.1×10^-3 at 5 μm. Additionally, the fundamental mode losses in the two orthogonal directions reduce to 10^-3 dB/m at 5 μm. We find that the proposed fiber can achieve high birefringence in the mid-infrared. Furthermore, the fiber is fabricated based on chalcogenide glass extrusion technology, and its birefringence can reach up to 4.6×10^-3 at 5 μm. This study reports all simulation and experimental results for such a suspended-core chalcogenide fiber in the mid-infrared and shows the possibility of a high-birefringence fiber device.