The phenomenon of microwave fluctuation before impending strong earthquakes is a type of anomalous pulsation record; its dominant frequency of spectrum focuses on 11-16 Hz and frequency spectral morphology appears fairly orderly. Microwave fluctuations occurred before the Wenchuan, Yushu, Qingchuan, and other strong earthquakes, and they can be used for predicting the strength of impending strong earthquakes. To conduct a tracing test on such microwave fluctuations, continuous records of microtremors were analyzed using the "real-time monitoring technology system of microtremor in Lanzhou"; these microtremors occurred in the three months before four M ≥ 5.5 earthquakes which occurred in the Qinghai-Tibet Block and Xinjiang area during 2015 and 2016. The reproducibility of the microwave fluctuation of impending earthquakes was verified by the abnormal amplitude change and duration of microwave fluctuation. The tracking test results were in accordance with seismic tracking indexes based on the microwave fluctuation preceding impending earthquakes proposed by Yang Liming.