Abstract: The regional time-length algorithm (RTL) was used to retrospectively examine the M_s5.2 earthquake at the boundary between Guangxi Beiliu and Guangdong Huazhou on October 12, 2019. The catalogue of earthquakes above M_L2.0 measured by China Earthquake Networks from October 11, 2015 to October 10, 2019 was selected, and the selection scope was determined according to the region near the epicenter: 49 points were obtained in the range of 109.0°~ 112.0°E and 20.5°~ 23.5°N with step size of 0.5°. RTL values of each point were calculated. The analysis results show that there are 8 RTL anomalies at the epicenter and its north and south sides before the earthquake, and the RTL analysis method can be used as an anomaly index before the earthquake.