The　modification　of　ZnS　by　doping　method　is　one　of　the　important　directions　in　the　research　of　ZnS　nano　materials.　Doping　of　transition　metal　ions　in　the　ZnS　matrix　has　attracted　much　attention　in　recent　years.　Doping　transition　metal　ions　can　modulate　the　emission　region　of　ZnS,　and　improve　the　efficiency　of　fluorescence.　The　doping　concentration　in　ZnS　has　determined　the　distribution,　absorption,　excitation,　emission,　and　structural　properties　of　particles.　Due　to　ZnS:Co　crystal　materials　have　the　best　characteristics:　the　stability　of　the　mechanical　properties,　high　emission　cross　section　and　wide　bandgap　tuning　at　room　temperature.　So　the　ZnS:　Co　film　is　grown　by　pulsed　laser　deposition　and　the　near　infrared　spectrum　properties　have　analyzed　that　have　researched　in　theory　and　experiment.　We　change　the　pressure　in　the　vacuum　chamber　by　controlling　the　pressure　of　the　argon　gas　to　fabricated　the　ZnS:　Co　film　by　PLD,　at　the　same　time,　we　chose　three　kinds　of　materials　as　the　substrate　of　the　thin　film,　and　compared　the　characteristics　of　the　thin　films.　This　method　has　the　advantages　of　short　fabrication　time　and　material　saving,　so　it　is　good　for　to　detect　and　research　the　optical　properties　of　the　films　of　ZnS:　Co.　A　variety　of　film　detection　of　X-ray　diffraction,　laser　particle　size　analyzer,　UV-Vis　spectrophotometer,　fluorescence　spectrophotometer,　morphology,　the　particle　size　and　optical　properties　of　the　samples　have　tested.　From　the　results,　the　infrared　transmittance　of　the　Co　doped　ZnS　is　almost　above　90%,　and　the　transmission　capacity　increases　with　the　increase　of　pressure.　The　film　thickness　decreases　with　the　increase　of　pressure　and　there　is　a　sharp　peak　in　absorption　spectrum,　this　point　has　important　significance　for　studying　photoluminescence　of　the　near　infrared　spectrum.