This paper investigates the risk assessment of subsynchronous resonance for series compensated UHV transmission of Ximeng coal-fired power base, which exemplifies a common problem in the development of the power grid in China. To avoid the problem of huge computational amount of offline analysis on subsynchronous resonance, a new method of online analysis and forewarning based on time-domain simulation is proposed. In addition, various suppression measures are summarized and discussed, as well as combination of multiple measures.