在底抽巷水力排渣仰角钻孔施工过程中，随着钻孔深度的增加，加接钻杆返水时间过长，且返水过程中伴随着大量高浓度瓦斯从钻杆尾部喷出，引起瓦斯异常升高或瓦斯超限事故；另外，在穿煤和水力冲孔期间钻杆回水等待时间，还会出现钻杆抱死等埋钻事故，增加瓦斯治理成本。为了解决这一安全隐患，以云盖山矿区21114综采面回采区域穿层钻孔工程为研究对象，根据底抽巷仰角钻孔的特性，创新设计了钻杆防回水装置，实践表明，该装置在加接钻杆期间有效解决了防回水装置上部的积水和瓦斯从钻杆尾部喷出的问题，保证了打钻作业的安全，提高了工效。

 In the construction process of hydraulic slag discharge elevation drilling in the bottom drainage roadway, with the increase of drilling depth, the return time of the drill pipe is too long, and a large amount of high-concentration gas is ejected from the tail of the drill pipe during the return process, causing abnormal gas increase or gas overrun accident. In addition, during the period of coal crossing and hydraulic punching, the waiting time of the drill pipe returning water will also appear buried drilling accidents such as drill pipe locking, which will increase the cost of gas control. In order to solve this safety hazard, taking the cross-layer drilling project in the mining area of 21114 fully mechanized mining face in Yungaishan mining area as the research object, according to the characteristics of the elevation angle drilling in the bottom pumping roadway, the anti-backwater device of the drill pipe is innovatively designed. The practice shows that the device effectively solves the problem of water accumulation and gas emission from the tail of the drill pipe in the upper part of the anti-backwater device during the period of adding the drill pipe, which ensures the safety of the drilling operation and improves the work efficiency.