Superlattice materials have become the preferred materials for the third-generation infrared focal plane 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. In this paper， it reports research results of 320 × 256 dual-color mid-mid-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 from the detector is 30 μm. At 77 K measurement， the SMW detector has a peak detectivity of 7.2×10¹¹ cm·Hz^1/2W^-1 and dead pixels rate of 0.49%. The MW detector has a peak detectivity of 6.7×10¹¹ cm·Hz^1/2W^-1and dead pixels rate of 0.87%. Infrared images of both wavebands have been taken well-infrared imaging test by adjusting devices voltage bias．