CO₂ geological storage in deep coal has become one of the important means for unconventional energy gas injection and production enhancement，as well as achieving regional carbon negative emission targets. Five coal-accumulating units in the Caoxian and Shanxian coalfields of southwest Shandong were focused，targeting the Shanxi Formation No.3 deep coal seam，to explore the potential of CO₂ geological storage in different coal-bearing units. Firstly，based on the supercritical carbon dioxide phase state mechanism，the critical depth for CO₂ storage in the target coal seam was defined，and the feasibility of CO₂ geological storage was discussed. Secondly，the blocks and units for CO₂ geological storage were divided according to the principle of decreasing order of structure（faults and folds）and burial depth.On this basis，the calculation of CO₂ adsorption capacity and free gas content was carried out in units of storage cells. Finally，the main controlling factors of CO₂ geological storage were identified by using the analytic hierarchy process（AHP）and principal component analysis（PCA）. And a fuzzy comprehensive evaluation system was used to divide the favorable areas for deep coal seam CO₂ geological storage in southwestern Shandong Province. The findings show that the structural conditions of the deep coal seams in the Caoxian and Shanxian coalfields are relatively simple，with the coal seam burial depths of 800~2 000 m（reaching the critical depth of supercritical state CO₂ geological storage），providing good conditions for CO₂ storage. The main controlling factors of the effectiveness of deep coal seam CO₂ geological storage are permeability and porosity. Through the fuzzy comprehensive evaluation system，it is determined that there are 6 blocks in the Caoxian coalfield，and the blocks is categorized into three classes of favorable areas. Class I advantage areas are blocks 2 and 5，with the sequestration capacity of 244 Mt and the sequestration area of 310.65 km². Class II advantage areas are blocks 1 and 6，with the sequestration capacity of 191.7 Mt and the sequestration area of 248.63 km². Class III advantage areas are blocks 3 and 4，with the sequestration capacity of 79.83 Mt and the sequestration area of 101.39 km²，indicating its for CO₂ geological storage potential is the greatest.