Abstract: With the increase of new energy penetration, the inertia and damping of the power system gradually decrease, and the transient power angle stability problem becomes increasingly prominent. In order to further evaluate the transient power angle stability of power system, it is necessary to quantitatively describe the transient power angle stability margin. In this paper, four main transient power angle stability margin calculation methods are summarized, including the maximum power angle difference margin calculation method, the fault critical removal time margin calculation method, the trajectory analysis margin calculation method and the generator power angle trajectory cluster integration margin calculation method. The adaptability and accuracy of four calculation methods were compared, providing useful references for further research on related issues.