Abstract: From December 2018 to November 2019, there are five significant anomalies of prediction index of geomagnetic diurnal variation in Guangxi and its adjacent areas, and several earthquakes with Ms≥4.2 occurred near the threshold line of the prediction index anomaly. Its internal relationship is worth exploring. This paper study their relationship and discusses the applicability of these prediction index in less seismicity areas similar to Guangxi. The results show that the anomalies of geomagnetic load-unload response ratio, geomagnetic daily ratio and geomagnetic low-point displacement in Guangxi and its adjacent areas are well corresponding to earthquakes with Ms≥4.9 occurring near the anomaly threshold line recently. The seismic parameters of original time, epicenter and magnitude basically meet to the prediction rules of current geomagnetic prediction indexes. In consideration density of geomagnetic observation and tectonic background, it is reasonable to appropriate relax the prediction rules for weak seismic region in practice sometimes. The prediction time of geomagnetic loading-unloading response ratio and daily ratio index in Guangxi and its adjacent areas is within 12 months, and the prediction location focuses on the area 200±50 km near the threshold line. These phenomena of one abnormal prediction index of geomagnetic diurnal variation corresponding to several earthquakes and one significant earthquake corresponding to several abnormal prediction index of geomagnetic diurnal variation are existing.