Patients　with　epidermal　growth　factor　receptor　mutant　nonsmall　cell　lung　cancer　(NSCLC)　often　fail　to　treat　gefitinib　because　of　secondary　drug　resistance.　The　development　of　tumor　drug　resistance　is　closely　related　to　variations　in　cancer　cell　metabolism.　Single-cell　metabolomics　analysis　can　provide　unique　information　about　tumor　drug　resistance.　Herein,　we　constructed　a　platform　to　study　the　secondary　resistance　of　tumor　cells　based　on　single-cell　metabolomics　(sSRTC-scM).　A　gefitinib-resistant　NSCLC　cell　line　(PC9GR)　was　constructed　by　increasing　the　dose　step　by　step.　The　metabolic　profiles　of　parental　PC9　cells　and　PC9GR　cells　with　different　drug　resistance　levels　were　detected　by　intact　living-cell　electrolaunching　ionization　mass　spectrometry　at　the　single-cell　level.　The　data　were　analyzed　by　statistical　methods　such　as　t-SNE,　variance,　volcano　plot,　heat　map,　and　metabolic　pathway　analysis.　Using　this　platform,　we　found　that　the　metabolic　fingerprints　of　PC9GR　cells　can　evaluate　drug　resistance　degrees.　The　metabolic　fingerprints　continue　to　be　altered　with　the　increase　of　drug　resistance.　We　revealed　19　metabolic　markers　of　secondary　resistance　by　variance　analysis　and　clarified　that　the　glycerophospholipid　metabolic　pathway　of　PC9GR　cells　changed　significantly.　In　addition,　we　found　that　with　the　increase　in　drug　resistance　levels,　the　heterogeneity　of　single-cell　metabolism　became　greater　and　the　number　of　cells　with　weak　drug　resistance　gradually　decreased.　This　phenomenon　can　be　utilized　to　illustrate　the　drug　resistance　degrees　of　PC9GR　cells.　This　study　provides　diagnostic　markers　for　evaluating　the　drug　resistance　of　tumors　and　gives　new　insight　into　overcoming　the　secondary　resistance　of　tumors.