在全球变暖的背景下，昆仑山北坡极端暴雨频发且影响巨大，由于对其的观测和研究相对匮乏，使得该区域暴雨监测和预报难度大。理解其发生机理和关键影响系统是提高其监测预报的有效途径，对该区域防灾减灾意义重大。利用高时空分辨率的气象观测资料、GPS/Met大气可降水量（PWV）资料、风云卫星资料（FY-2H）和ERA5再分析资料，对2021年6月14—17日昆仑山北坡一次极端暴雨过程进行大尺度环流背景场和中尺度对流系统特征分析。结果表明：（1）此次暴雨过程，暴雨站数多、累积降水量大、局地性强并且极端性强，在和田地区出现3个极端暴雨中心，分别发生了短时强降水和连续性降水。其中短时强降水过程持续时间短，最大小时雨强达29.4 mm；连续性降水持续时间达3 d，小时雨强小于5 mm。本次极端暴雨发生的有利环流背景是双体型南亚高压在对流层高层维持，中亚低涡形成发展。在高低空急流共同作用下，高层强辐散、低层辐合促进大气垂直运动发展，500 hPa偏南气流、700 hPa切变线以及850 hPa偏东气流相互配合为暴雨提供有利动力配置。（2）对流层中层以西南路径和西南+南方路径水汽输送为主，低层主要以低空偏东急流携带水汽输送为主，中低层水汽输送路径形成耦合，促进本次极端暴雨的发展加强。极端暴雨发生前持续的水汽输送和强的水汽通量辐合中心，使得暴雨区大气可降水量（PWV）在降水前出现显著增湿聚集过程，PWV达30 mm。（3）列车效应型+合并加强型中尺度对流云团不断在暴雨站点上空生成发展并移过，是触发短时强降水的直接影响系统，站点位于对流云团黑体亮温（TBB）梯度最大处。中-β和中-α尺度对流云团发展维持以及涡旋状中尺度对流云带的持续覆盖，是导致暴雨站点发生连续性降水的关键系统。

In this paper, we use meteorological observations with high temporal and spatial variability [Fengyun satellite data (FY-2H), GPS/Met atmospheric precipitable water volume (PWV) data, and ERA5 reanalysis data]to characterize the large-scale circulation background field and mesoscale convective system (MCS) of an extreme rainstorm process on the northern slope of the Kunlun Mountains from June 14 to 17, 2021. The results showed the following. (1) The rainstorm process was characterized by many rainstorm stations and large cumulative precipitation, both localized and extreme. There were three extreme rainstorm centers in the Hotan Prefecture, where short-term heavy precipitation and continuous precipitation occurred, respectively. The duration of the short-term heavy precipitation process was short, with a maximum hourly rainfall of 29.4 mm. Meanwhile, the duration of continuous precipitation was 3 days, with an hourly rainfall of less than 5 mm. The upper troposphere was maintained by a two-body South Asian high pressure, and the formation and development of the Central Asian low vortex was a favorable circulation background for the occurrence of this extreme rainstorm. Under the joint action of high- and low-altitude rapids, strong dispersion in the upper level and convergence in the lower level promoted the development of vertical movement of the atmosphere. Moreover, a 500-hPa southerly flow, a 700-hPa shear line, and an 850-hPa easterly flow jointly provide a favorable power configuration for the rainstorm. (2) The water vapor transport in the middle troposphere was dominated by a southwest path and a southwest+south path, whereas that in the lower layer was dominated by a low-level easterly jet stream. The coupling of the water vapor transport paths in the middle and lower layers promoted the development and strengthening of this extreme rainstorm. The continuous moisture transport and strong water vapor flux convergence center before the occurrence of the extreme rainstorm made the atmospheric PWV in the rainstorm area show a significant humidification and gathering process before the precipitation, with the PWV reaching 30 mm. (3) Train-effect-type+merging- and intensifying-type MCSs were continuously generated over the rainstorm station and moved through, attributed to the direct influence system triggering short-term heavy precipitation, and the station was located at the maximum of the TBB gradient of the MCSs. The development and maintenance of meso-β- and meso-α-scale MCSs and the continuous coverage of vortex-like mesoscale convective cloud bands were the key systems that led to the occurrence of persistent precipitation at the storm site.