Abstract: In order to obtain the influence radius of deep-hole pre-cracking by tandem type commection of carbon dioxide fracturing devices, two groups of experiments were carried out in No.3 coal seam of a coal mine in Shanxi province to study the influence radius under two different working conditions of extraction area and non-extraction area, and combined with the theoretical calculation, the results were analyzed. The results show that the influence radius is about 5 m when the drilling depth is 100 m through tandem type commection of carbon dioxide fracturing devices. It provides a strong technical support for the fracturing and permeability improvement design and field construction.