In the application of TCSC（thyristor controlled series compensation）, the parameters of TCSC are very important for its characteristics. According to the data of transmission lines, the parameters of the TCSC are correctly designed. Then based on that, it established the models of FSC（fixed series compensation）and TCSC+FSC power system separately. With the presented study of FSC and TCSC+FSC power system, the results indicated that the TCSC+FSC power system is more efficiency than FSC power system on damping SSR(sub-synchronous resonance).