Confinement　effect　from　steel　tube　to　concrete　core　is　the　main　advantage　of　concrete-filled　steel　tubular　(CFST)　structures.　However,　this　beneficial　composite　action　would　be　weekened　even　destroyed　by　debonding,　while　debonding　is　almost　unavoidable　in　CFST　arches.　In　this　paper,　finite　element　models　of　the　CFST　columns　with　various　debonding　arc-length　ratios　were　implemented　using　the　general　purpose　ABAQUS　finite　element　software,　where　the　validity　was　verified　by　test　results.　Utilizing　this　modeling　method,　the　finite　element　models　of　the　CFST　single　tube　arch　with　various　debonding　arc-length　ratios　were　also　bulit　by　ABAQUS.　Based　on　the　equivalent　beam-column　method,　a　simplified　calculation　formula　is　proposed　to　depict　the　ultimate　load　capacity　of　CFST　single　tube　arches　with　debonding.