Abstract: For the technical problems that long drainage standard time is difficult to meet the needs of high production and efficiency by using a single underground extraction or ground extraction method for high gas mine in our country, theoretical analysis was carried out with the laboratory of hydraulic fracturing and numerical simulation. The influence factors of crack propagation were analyzed. The theory calculation method of ground fracturing crack propagation are given, which provides theoretical support for the ground fracturing fracture-making and design of hole arrangement. The key parameters of reasonable space and time connection between ground fracturing operation and underground extraction drill hole were studied. The fracturing and extraction joint and the safe connection between ground fracturing well and underground extraction drill hole were realized. It improves mine gas extraction efficiency and provides effective guarantee for mine safety production.