In this paper, an integrated approach combining the calculation of electrical damping versus frequency and time domain simulation is applied in analyzing the SSR problem of Tuoketuo Power Plant caused by its series compensation transmission scheme. Firstly, the electrical damping versus frequency in different series compensation degrees and different operating conditions is calculated using the test signal method; secondly, based on the calculated electrical damping, the required minimum mechanical damping for stabilizing SSR is calculated, and the required minimum mechanical damping is compared with the real mechanical damping of the Tuoketuo Power Plant machines to determine the stability of SSR; finally, based on the multi-mass model of the machines, time domain simulation using PSCAD/EMTDC is performed to verify the above results and to study some operating conditions that can not be studied by the electrical damping versus frequency characteristics. The final results of the paper can be used as guidance to design the series compensation transmission scheme for Tuoketuo Power Plant phase four