Abstract: This research studies the key control technology in the process of hard roof loosening blasting, with Zhangji Mine of Huainan, Anhui as the background of the field test, combined with numerical simulation.Numerical simulation of the deep hole loosening blasting of the slitting charge was carried out.The field comparison test of the ordinary charge control blasting and the slitting charge was conducted.The results show that the proposed combined technology of loosening pre-splitting of ultra-deep holes in the huge and hard roof and directional fracture of the slitting charge can increase the directional expansion range of blasting cracks and solve the problem of excessively large bottom hole spacing in ultra-deep hole loosening pre-splitting blasthole blasting and so as to achieve precise control of the blasting fracture surface and the collapse position of the hard roof; artificially regulate the interval of periodic weighting, so that the hard roof can collapse in time and safely, and the working face can mine continuously and safely.