In this paper,we conducted a regression analysis of the data of the intensity distribution of 146 earthquakes(M≥5.0)which occurred in the period from 1900 to 2014. According to the previous research results,Yunnan is divided into 3 tectonic regions. Then,we use the data of the isoseismic lines in these 3 regions to fit the intensity-attenuation model of each region. Since there are a few earthquakes with M≥7.0 in this defined 114-year period,the fitted intensity-attenuation model of the strong earthquakes would be random or uncertain. To solve this problem,we introduce the Rupture scale relation to limiting our fitted intensity-attenuation model of the strong earthquakes. We choose the empirical relation of magnitude and rupture-scale,which was proposed by Li Zhonghua and Qin Jiazheng,to correct the size of the influence field estimated through our intensity-attenuation model. Comparing our intensity-attenuation models with the previous ones,we found that,in a certain tectonic region,the intensity isoseismal estimated through our model averagely have minimum error with the real intensity isoseismal decided through the field investigation. Therefore,it is more advisable to choose the small-scale zone for the intensity-attenuation evaluation.