Transient stability constrained total transfer capability is one of common power system calculation. In this paper, a practical total transfer capability calculation method considering transient stability constraints is proposed, which can be applied to large interconnected power systems. The main advantages of the proposed method includes: Load flow calculation convergence at each operation in the process oftransient stability constrained total transfer capability calculation can be unproved greatly; active and reactive power of generators and loads can be adjusted automatically according to specified rule; reactive power compensation such as shunt capacitor, shunt reactor, etc can be considered automatically, w hich means that reactive power compensation can be switched on or off according to the change of power system operation point For the further application to the large interconnectedpower system, this paper initially designed distributed computing architecture to enhance efficiency of fault check based on PSASP@bome. In the end, software developed by this paper for transient stability constrained total transfer capability calculation is introduced.