Abstract: The deep coal reservoir in Qinshui Basin has the geological characteristics of low permeability to ultra-low permeability, local high saturation, low porosity and high thermal evolution degree. Under the development mode of vertical well/horizontal well + large-scale fracturing, it is necessary to adapt the completion technology to ensure the reservoir reconstruction and late production effect. This paper systematically analyzes the different well structure and tool types of conventional single casing completion technology, open hole/screen completion technology, casing + slip-sleeve completion technology, and discusses the applicable conditions and technical characteristics of different completion technologies. The results show that the conventional single-casing completion technology is mature, and the three-way completion structure is widely used, but it is not conducive to cost reduction and efficiency increase. The second well completion structure is only applicable to the geological conditions where the overlying strata is relatively stable and there is no aquifer or weak aquifer. Open hole/screen completion technology can reduce the pollution of coal section, but it can not carry out late reservoir transformation, and is suitable for the reservoir with complete coal structure and strong permeability of coal seam. Casing + slip-sleeve completion can eliminate perforation before fracturing, but the normal operation of downhole tools is not guaranteed and the fracturing rate is limited in the later stage. For producing vertical Wells in U-shaped development Wells, a new double-casing completion technology was proposed on the premise that the wellbore could not meet large-scale fracturing operations. The principle of this technology is to reshape the wellbore by selecting casing and cementing tools according to geological conditions and characteristics of the old wellbore, so as to meet the late fracturing process and ensure the fracturing reconstruction effect. It is mainly characterized by the use of cement sealing above the roof of the target coal seam, with high pressure resistance and large inner diameter casing, so that the wellbore can meet the large-scale fracturing of high construction pressure. At the same time, the selection of screen pipe in the coal seam saves the perforation cost, and can effectively avoid the formation collapse and bury the coal seam in the drainage stage. The technology has been successfully applied in deep coal reservoirs in Qinshui basin, and the test results show that it can meet the needs of deep coalbed methane fracturing operations under large scale and high construction pressure, and has the prospect of popularization.