Taking Bijie tobacco planting area in Guizhou Province as the study area, based on the analysis of different influential factors on soil pH, the main controlling factors of soil pH variation were discussed, the spatial variation characteristics of soil pH were obtained by geostatistical interpolation method, and then the suitability grades of carbon-based organic fertilizer for improving acidified soil in this area were divided. The average value of soil pH in Bijie tobacco growing area is 6.5, the average value of soil pH in Dafang and Weining counties are both only 6.2, while those in Zhijin, Jinsha and Qianxi counties are all higher than 7.0. The comparative analysis shows that soil parent rock and soil types are the main controlling factors of soil pH variability in Bijie tobacco growing area. From the perspective of spatial distribution characteristics, soil pH distribution is higher in the east than those in the middle and west. Soil pH is higher in the northwest of Jinsha County, the east of Dafang County, and the middle of Qianxi County; lower in the south of Weining County, the middle and north of Hezhang County, and the middle and west of Qixingguan as a whole, the area proportion of soil pH is about 44.1% in the appropriate grade (5.5