In this paper， the research results of 12.5 μm long-wavelength infrared InAs/GaSb superlattice focal plane arrays were reported. The superlattice structure was grown on GaSb substrate using molecular beam epitaxy （MBE） technology. The respective structure of absorption region is 15ML （ InAs） /7ML （ GaSb）. The detector adopts PBπBN double barrier structure to suppress the dark current. A long-wave focal plane detector with the size of 1 024×1 024 and the pixel center-to-center distance of 18 μm was developed. The detector was packaged by a metal dewar， and a superlattice long-wavelength detector cryocooler assembly was formed by coupling with a refrigerator. Measured at 60 K， the detector has 50% cut-off wavelength of 12.5 μm. The detector has a peak detectivity of 6.6×10¹⁰ cm?Hz^1/2/W ， dead pixels rate of 1.05% and a noise equivalent temperature difference （NETD） of 21.2 mK.The infrared images have been taken clearly using this infrared imaging detector.