The invention provides an InAs/GaSb superlattice infrared photoelectric detector and a manufacturing method thereof. The InAs/GaSb superlattice infrared photoelectric detector comprises a substrate, an epitaxy structure deposited on the substrate, an upper metal electrode formed above steps, a lower metal electrode formed under the steps and a passivation layer, wherein the epitaxy structure comprises an n-type doping buffer layer, an n-type electrode contact layer, a barrier layer, an intrinsic absorption layer, a p-type electrode contact layer and a cover layer, the steps are formed on two sides of the epitaxy structure through etching, the intrinsic absorption layer is composed of a plurality of periodical InAs/InSb/GaSb/ InSb superlattice structures. In the InAs/GaSb superlattice infrared photoelectric detector, InSb is respectively inserted into two interfaces of each superlattice period of the intrinsic absorption layer to form strained superlattices, the stress between the superlattices and the substrate is effectively balanced, the material growing quality is improved, and accordingly the photoelectric performance of the detector is improved.