With the advancement of infrared technology, infrared detector assemblies are developing towards smaller size and higher resolution. Small pitch and large area array specifications are important directions for the development of long-wavelength detectors. Through the research of 10 μm pitch, 9 μm cut-off wavelength, and 1280×1024 long-wave detector arrays, breakthroughs have been made in 10 μm-pitch long-wavelength pixel junction technology, 10 μm-pitch indium column preparation and interconnection technology. A long-wavelength 1280×1024 HgCdTe detector chip with an effective pixel rate of 99.4% or more and a non-uniformity of less than or equal to 4% has been developed.