Abstract: Aiming at the problem that it is easy to cause mine disasters because of the large roof caving step of hard roof coal face in the early mining, selecting the 8935 working face of Xinzhouyao Coal Mine as the research object, the method of deep-hole pre-splitting explosion weakening roof is proposed. According to the related blasting theory and the theory of mechanics, in combination with the practical condition of 8935 working face, through the analysis of the mechanism of deep-hole pre-splitting explosion weakening roof, the parameters for deep hole pre-splitting blasting are optimized, and the field tests are carried out. Experimental results showed that mine pressure appear is not sharp during the first weighting, the first caving step of immediate roof is about 13 m, and the first weighting step of basic roof is about 34 m; support working resistance slightly increases after blasting, the concentration of CH₄ and CO increases for a short period of time; when the top coal falls down in time, it can recycle 33.2 m long coal. Tests show that deep hole pre-splitting blasting plays an obvious role in weakening of roof and can reduce related disasters and increase the top-coal recovery efficiency.