Earthquake intensity distribution is an important basis for the rapid assessment of disaster losses, emergency rescue, and restoration and reconstruction after the earthquake. At present, the seismic intensity circle is mainly drawn manually according to the intensity survey points obtained from field survey by using the GIS software. However, the traditional method is inefficient and time-consuming. In this paper, a method of automatic delineation of seismic intensity circle was proposed. First of all, the factors affecting seismic intensity mapping were fully considered. According to the aftershocks distribution and the types of seismogenic faults, the location of macro epicenter and the long axis direction of intensity circle can be determined. Then, the envelope was generated based on the maximum discrete intensity points. The statistical relationship between the maximum intensity and the area of intensity circle was taken as the constraint condition, and the maximum intensity circle was obtained by using the adaptive algorithm. Finally, combined with different discrete intensity points, other intensity circles were obtained by using the above-mentioned method, and the Jiuzhaigou M7.0 earthquake was taken as an example. The experimental results showed that the proposed method can automatically generate intensity circle, and the accuracy of intensity circle generated by discrete intensity points obtained from the fusion of multi-source disaster information in 28 hours after the earthquake is over 80%. The method effectively improves the delineation efficiency of earthquake intensity circle, and can provide support for the rapid development of earthquake emergency rescue work.