In long-wave infrared region, InAs/GaSb type-Ⅱ superlattice material has more superior performance than HgCdTe, thus has been widely studied. A series of experiments were carried out on the InAs/GaSb type-Ⅱ superlattice infrared detector to improve the technology level of back thinning. For <100> GaSb single wafers, different single-point diamond turning (SPDT), mechanical chemical polishing and chemical polishing methods were studied. The machining damage was removed. Through the experiments of InAs/GaSb type-Ⅱ superlattice infrared devices, good infrared imaging pictures were obtained by the long-wave detector assembly, which can improve the technology level of InAs/GaSb type-Ⅱ superlattice long-wave infrared detector.