Flow cytometry detection of the proportion change trend of inductive formation CD3+CD8-IL-17+Th17 cells after isolation co culture of cord blood initial T cells combined with papillary thyroid cancer cell lineage (TPC-1 and K1) and normal thyroid follicular epithelial cell line (Nthy ori 3-1) treated for 24 h, 36 h, 48 h, 60 h. The results of co-culture with Nthy ori 3-1 were 7.26 ± 2.14 in 0 h, 9.07 ± 1.33 in 24 h, 10.70 ± 1.45 in 36 h, 8.70 ± 1.87 in 48 h, 9.57 ± 1.29 in 60 h. The results of co-culture with TPC-1 were 7.85 ± 1.50 in 0 h, 18.77 ± 1.45 in 24 h, 24.00 ± 1.68 in 36 h, 13.83 ± 2.25 in 48 h, 9.57 ± 1.29 in 60 h. The results of co-culture with K1 were 7.88 ± 2.84 in 0 h, 19.63 ± 1.81 in 24 h, 43.30 ± 2.86 in 36 h, 24.03 ± 1.78 in 48 h, 32.63 ± 3.25 in 60 h. Symbol *indicate significance at the 0.05 level, symbol **indicate significance at the 0.01 level, symbol ***indicate significance at the 0.001 level.