In　this　paper,　the　method　of　thin　film　preparation　is　pulsed　laser　deposition　(PLD).　ZnS:Co　thin　film　was　grown　on　sapphire　and　glass　substrates　at　different　temperatures　(pressures)　by　PLD,　and　we　studied　a　series　of　optical　properties.　It　shows　the　crystal　structure　in　XRD.　The　transmission　spectral　properties　of　the　ZnS:Co　film　are　very　prominent.　The　transmittance　of　the　film　is　over　90%　between　800　and　6000　nm.　The　XRD　results　show　the　crystalline　structure　of　the　film　on　sapphire　substrates　and　the　amorphous　structure　of　the　film　on　glass,　which　is　reflected　in　the　guidance　effect　of　the　substrates.　The　high　temperature　environment　is　conducive　to　the　formation　of　crystals.　The　best　electrical　properties　of　film　with　600　degrees　C　proposed　in　the　experiment.　The　research　results　play　a　key　role　in　the　application　of　ZnS:Co　materials.