深部煤层瓦斯含量精准测定是矿井瓦斯灾害防治和煤层气高效开发利用的基本前提。煤层传统取心技术普遍采用开放式取心，需利用估算方法获得煤层取心过程中的瓦斯损失量，难以保证煤层瓦斯原位参数的准确性和有效性。基于“原位保真取心”学术思想，开发了深部煤层原位保压保瓦斯取心技术，研制了深部煤矿原位保压保瓦斯取心器， 并基于三维数值仿真对取心器外管、保压舱体结构与关键薄弱部件进行了强度校核。同时，依托自主研发的保压取心实验室模拟测试平台，测定并分析了保压控制器的保压能力，通过煤矿现场试验验证了取心器的可靠性。研究结果表明：自主研制的取心器具有保压能力强、保压时间长、防扰动性能稳定等优势；取心器在内部流体压力20 MPa和1000 N$ cdot $m扭矩作用下等效应力为121.1 MPa，远小于材料屈服强度，满足强度设计要求；取心器在20 MPa荷载作用下等效应力为63.9 MPa，满足强度设计要求；取心器整体在19.4 MPa压力条件内可持续稳定运行，可以满足大部分深部煤矿瓦斯测试需求；现场测试表明保压保瓦斯取心器的保压控制器闭合情况良好，现场取心率达100%。研究成果可为深部煤层瓦斯含量精准测定奠定理论、技术和装备基础，对于煤矿瓦斯灾害防治和煤层气勘探开发具有重要意义。

Accurate determination of gas content in deep coal mine is the premise for the prevention and control of gas disaster, as well as the efficient development and utilization of coalbed methane. Traditional coring technology of coal seam is generally open-ended and requires to obtain the amount of gas loss during the coring process by using estimation methods, making it difficult to ensure the accuracy and validity of the in-situ parameters of coalbed methane. Based on the academic idea of “in-site condition-maintaining coring”, the in-situ pressure- and gas-maintaining coring technology for deep coal seam was proposed, and the in-situ pressure- and gas-maintaining corer for deep coal seam was developed. The strength verification for corer outer tube, pressure-maintaining chamber and key weak parts were conducted based on three-dimensional numerical simulation. Meanwhile, the pressure-maintaining capacity of controller was measured and analysed relied on the self-developed pressure-maintaining coring laboratory simulation test platform, and the reliability of corer was verified through field tests in coal mine. The results shown that, the self-developed corer had the advantages of strong pressure-maintaining capacity, long pressure-maintaining time and stable anti-disturbance performance. The equivalent stress of the corer under internal fluid pressure of 20 MPa and torque of 1000 N·m was 121.1 MPa, which was much smaller than the yield strength of the material and met the strength design requirements. The equivalent stress of corer under the pressure of 20 MPa was 63.9 MPa, which met the strength design requirements. The corer can operate continuously and stably at the pressure of 19.4 MPa, which met the demand for gas testing in most of deep coal mines. The field test shown that, the pressure-maintaining controller of the pressure- and gas-maintaining corer closed well, with 100% of coring rate in the field. The research provides a theoretical, technical and equipment foundation for the accurate determination of gas content in deep coal seams, which is of great significance for the prevention and control of coal mine gas disasters and the exploration and development of coalbed methane.