Graphene-based　photodetectors　exhibit　relatively　low　spectral　absorption　and　rapid　recombination　of　photogenerated　carriers,　which　can　limit　their　response　performance.　On　the　other　hand,　nanostructured　lead　sulfide　(PbS)　demonstrates　a　wide　spectral　absorption　range　from　visible　to　near-infrared　light.　High-quality　and　evenly　distributed　PbS　nanofilms　were　synthesized　by　chemical　bath　deposition　and　were　applied　to　a　graphene-PbS　heterostructure　photodetector.　The　heterostructure　creates　an　inherent　electric　field　that　extends　the　lifetime　of　photogenerated　carriers,　leading　to　enhanced　device　response.　We　achieved　a　high-responsivity　graphene-PbS　photodetector　by　combining　the　high　carrier　mobility　of　graphene　and　the　strong　infrared　absorption　of　PbS.　The　photodetector　exhibits　a　responsivity　of　72　A/W　at　792　nm　and　5.8　A/W　at　1550　nm,　with　a　response　time　of　less　than　20　ms.　The　optimized　device　features　a　broad　spectral　response　ranging　from　265　nm　to　2200　nm.