Graphene　has　become　a　promising　material　for　photodetection　applications　due　to　its　superior　electrical　and　optical　properties　with　mobility　excessed　2　x　10(5)　cm(2)　V(-1)s(-1)　in　a　broadband　wavelength　regime　from　UV　to　THz.　However,　the　photoresponsivity　is　limited　by　the　low　absorption　and　ultrafast　recombination　of　photogenerated　carriers.　Here,　we　designed　and　simulated　a　graphene/HgCdTe　heterostructure　with　optimizing　numerical　parameters　of　hybrid　graphene　and　HgCdTe.　The　independent　effects　of　doping　concentration,　band　gap,　electron　affinity,　thickness,　temperature,　alloy　composition　etc.　on　photodetector　performance　have　been　studied.　Generally,　we　have　demonstrated　that　the　combination　of　n-type　HgCdTe　and　p-type　graphene　can　construct　a　Schottky　junction　to　effectively　dissociate　photogenerated　electron-hole　pairs,　resulting　in　a　highest　external　quantum　efficiency　of　69.06　%　at　3　mu　m　and　maximum　high　responsivity　of　2.60　AW(-1)　in　visible　to　mid-infrared　wavelength　region　(0.5　similar　to　5.2　mu　m).　These　results　contribute　to　offer　a　novel　and　versatile　strategy　for　constructing　the　graphene/HgCdTe　heterostructure　infrared　photodetectors.