To analyze the main chemical constituents of Veratrum dahuricum, and study their antibladder cancer activity. Chloroform and ethyl acetate fractions are obtained by ethanol extraction, and subsequent extraction with chloroform, ethyl acetate, saturated water and n-butanol. The fractions are then further purified through silica gel column chromatography, preparative HPLC, repeated silica gel column chromatography (chloroform-methanol), D101 macroporous resin column chromatography, Sephadex LH-20 gel column chromatography (methanol), C-18 reversed-phase silica gel column chromatography (methanol-water), preparative TLC and recrystallization. Inhibitory effect of resveratrol on T24 cells is observed by MTT assay and inverted microscopy. Six compounds are isolated from Veratrum dahuricum, namely verzine, germitrine, quercetin, stigmasterol, polydatin and resveratrol. MTT assay results show that the test concentrations of resveratrol can effectively inhibit the proliferation of T24 cells. The inhibitory effect is enhanced gradually with increasing drug concentration, showing a certain dose-response relationship. Under inverted microscope, adherently growing cells are visible in the control group, with tight and full intercellular junction and intact membranes. In the test group, cell growth density becomes gradually sparse with increasing drug concentration, intercellular junction is loose, adherent capacity is clearly insufficient, cell surface is wrinkled, and cell debris is also plentiful. In the high concentration group, most cells are disrupted, cell morphology is incomplete, and adherent cells are reduced in number. Veratrum dahuricum can inhibit the proliferation of human bladder cancer T24 cells, which has a certain anti-cancer activity.