In this paper,the epicenter of the Jiuzhaigou M_S7.0 earthquake on August 8,2017 is taken as the center,and the evolution process of the precursory anomalies of different epicentral distances before the earthquake is analyzed. The result shows that there was no precursory anomaly within the range of 100km from the epicenter,and the precursory anomalies were mainly distributed in the epicentral distance from 100 to 500km. The number of new anomalies increased gradually 2 years before the earthquake. The ratio of anomaly items in different epicentral distances reached the maximum around 1.5 years before the earthquake and decreased again before the earthquake,and the ratio of abnormal items in the epicenter distance 300km was relatively high. There were three different stages of spatiotemporal evolution of precursory anomalies:during the α stage(early stage of precursory anomaly,including α₁ and α₂,more than 1000 days before the main earthquake),the anomalies are mainly distributed in the northeast and southwest of the epicentral area,It is shown that the precursors have the characteristics of outward expansion. During the β stage(Intermediate stage of precursory anomaly,between 500 to 1000 days before the main earthquake),there was a large range of anomalies. During the γ stage(Recent stage of precursory anomaly,including γ₁ and γ₂,500 days before the main earthquake),the anomalies were distributed in the northeast of the epicentral area. The anomalies converged to epicenter(γ₁)in the far source region and expanded outwards(γ₂)in the near source region. Compared with other earthquake cases,it is found that the three-stage phenomena of precursory anomalies may be the common characteristics before major earthquakes. The significant increase of precursory anomalies before major earthquakes has some indication significance for time prediction of earthquakes.