Superlattice materials have become the preferred materials for the third-generation infrared focal plane array detectors. The dual-band infrared detector can suppress the complex background and improve the detection effect by comparing the spectral information difference in the two bands, which is particularly important in demand. The research on the design and preparation technology of the InAs/InAsSb superlattice mid/middle dual- band focal plane array detector is carried out, and the research is carried out from the aspects of device design, material epitaxy, and chip processing. In this paper,we report research results of 320 × 256 dual- band mid/middle -wavelength infrared InAs /InAsSb superlattice focal plane arrays.The detector structure is NBN epitaxial multilayer and the signal is read out by sequential mode.The pixel center distance of the detectoris 30μm, At 77K measurement,The SMW peak detection rate of the device reaches 7.2 × 1011cm?Hz1/2W-1、NETD:19mK and dead pixel rate is 0.49%; The MW peak detection rate is 6.7×1011cm?Hz1/2W-1，NETD:12mK and dead pixel rate is 0.87%．A high-quality imaging effect is obtained, and a mid to middle two- band detection is achieved.