Abstract: With the continuous increase of mining depth in China’s deep mines, rock burst disasters frequently occur in the roof dynamic square area, which seriously endangers the safe production of mines. Taking the roof dynamic square area of deep mines as the research object, this paper systematically investigates the pressure relief and rock burst prevention mechanism of deep-hole pre-splitting blasting, and carries out numerical simulation and field verification. The results show that deep-hole pre-splitting blasting damages the roof rock mass structure through rock fragmentation induced by blasting dynamic load, detonation gas wedge effect and thermal-mechanical rebound, and reduces its energy storage capacity. This promotes the transformation of high-energy thick and hard roof into a stable low-energy state. Meanwhile, the interconnected blasting-induced fractures form structural weak planes and block the stress transmission paths, thereby realizing dual objectives of rock mass weakening and structural optimization. According to the single-factor numerical analysis on rock fracturing effect of blasting, the optimal combination of blasting parameters is determined as follows: hole diameter of 80 mm, decoupling charge coefficient of 1.17 and cartridge diameter of 60 mm. Under this condition, the blasting influence range is the largest and the fracturing effect is the best. The numerical simulation of 2106 working face indicates that the plastic zone of the roof is interconnected within the range of 30-60 m after pre-splitting blasting. As the working face advances, the high-position hard rock strata break and cave in timely, and the overhanging roof area is greatly reduced. Pre-splitting blasting reduces the vertical stress concentration above the section coal pillar by 10%, which effectively improves the stress state of coal pillars and high-position rock strata and facilitates the maintenance of the return airway. Field mine pressure and micro-seismic monitoring verify that deep-hole pre-splitting blasting can effectively reduce rock burst risks. However, continuous construction is required to avoid discontinuous stress transmission.