CdSe　quantum-dot　(QD)　film,　as　the　core　function　layer,　plays　a　key　role　in　various　optoelectronic　devices.　The　thickness　uniformity　of　QD　films　is　one　of　the　key　factors　to　determine　the　overall　photoelectric　performance.　Therefore,　it　is　important　to　obtain　the　thickness　distribution　of　large-area　QD　films.　However,　it　is　difficult　for　traditional　methods　to　quickly　get　the　information　related　to　its　thickness　distribution　without　introducing　additional　damage.　In　this　paper,　a　non-contact　and　non-destructive　inspection　method　for　in-situ　detecting　the　thickness　uniformity　of　CdSe　QD　film　is　proposed.　The　principle　behind　this　in-situ　inspection　method　is　that　the　photoluminescence　quenching　phenomenon　of　the　QD　film　would　occur　under　a　high　electric　field,　and　the　degree　of　photoluminescence　quenching　is　related　to　the　thickness　of　the　quantum　dot　films.　Photoluminescence　images　of　the　same　QD　film　without　and　with　an　electric　field　are　recorded　by　a　charge-coupled　device　camera,　respectively.　By　transforming　the　brightness　distribution　of　these　two　images,　we　can　intuitively　see　the　thickness　information　of　the　thin　film　array　of　QD.　The　proposed　method　provides　a　meaningful　inspection　for　the　manufacture　of　QD　based　light-emitting　display.　©　Science　China　Press　2024.