Based on the Gutenberg-Richer relation between earthquake magnitude and frequency, along with seismic data from the China Earthquake Networks Center since 2009, in this study, we analyzed the abnormal distribution of b-values prior to the Hutubi M_S6.2 earthquake in 2016. We used the maximum likelihood method to calculate the b-values for the epicentral and surrounding region prior to the Hutubi earthquake and obtained spatial images of the b-value in the study area. The results showed that there is a large area of low b-value anomalies prior to the Hutubi M_S6.2 earthquake, with the b-values ranging between 0.6-2.2, which indicates that this region is accumulating a high degree of horizontal stress. This anomaly may reflect the stress accumulation process in advance of an earthquake and prove the physical significance of the b-value.