Mechanical properties of CFT column and steel beam joint with inner stiffening ring was analyzed by using FEA program ANSYS. Simultaneity, using correlative theory of circular beam, stress distributing rule of stiffening ring was induced. The multi-dimensions joint is different from the annular plane in bidirectional. Not only the turn of beam-annular stress concentration, but also lied on the oblique angle, smaller of the angle easier to form the biggest stress area. Thickness of stiffening ring can impact on load absorption of enforced plane. Results of FEA are valuable methods for design of stiffening ring.