The latest research progress of SW/MW dual-band mercury cadmium telluride(MCT)materials and devices based on molecular beam epitaxy(MBE)is reported. High-quality SW/MW dual-band MCT materials are grown by the MBE method, and the surface defect density is controlled below 300 cm-2 by improving the material quality. On this basis, the chip fabrication process is further optimized, especially in terms of reducing the pixel pitch. A 320×256 SW/MW dual-band MCT infrared detector assembly is fabricated based on the above-mentioned various material and device processes. The results show that the test performance and imaging effect of the assembly are good.