The electrical energy of Xinjiang province and other northwestern regions in China will be sent to the power shortage areas by using wind-thermal-bundled power transmission system, however, the relatively weak grid structure and other factors often lead to irregular subsynchronous oscillation. Based on the previous research on the monitoring and control strategy of synchronous oscillation of wind farms, when the monitoring and control devices in wind farms don’t detect harmonic, and through the analysis of the causes and the propagation path of the harmonic, the monitoring system is established by PMUs and other installations at the best monitoring point-220 kV power grid, and the sequential safety control method is also put forward. Finally, the strategy is applied to the Mahuanggou area of Xinjiang province, and the feasibility of the strategy is verified by comparing the waveforms of the sampled values before and after the oscillation. This work is supported by National Natural Science Foundation of China (No. 51667020).