通过分析气候变暖背景下中国降水量的时空分布变化、降水强度等级分布的变化以及铁路降水警戒风险时数变化等，研究了气候变暖背景下降水变化对中国铁路安全运营秩序的影响。研究发现：（1）近5年，江南南部和华南等地年降水量显著减少；西北地区东部和西南地区东北部至江淮和黄淮等地降水量显著增加。年降水量最高的中国铁路广州、南昌和南宁集团有限公司（简称路局）辖区，年降水量呈减少趋势变化；郑州、济南和西安路局年降水量呈增加趋势变化。东亚夏季风增强，副热带高压偏北是降水量变化的主要原因。（2）全国降水强度变化分布不均，其中沈阳路局降水强度增强最显著，南宁路局降水强度减弱最显著。降水强度变化主要与台风和短时强降水的变化有关。（3）从降水强度等级分布看，近5年，乌鲁木齐和兰州路局等西北地区路局的较大降水强度的出现频率有所减少；南昌和成都路局等西南至江南地区路局的较大降水强度的出现频率有所增多。（4）广东和海南、西南地区东部、华北东北部至东北东南部是铁路降水出巡风险时数最多的3个高值区；限速风险时数的高值区位于西南地区东部；封锁风险时数的高值区范围进一步缩小。综合来看，在气候变暖的背景下，中国江南南部和华南等地的降水量显著减少，降水时数和铁路出巡风险时数有所减少，铁路限速风险时数略有减少，铁路降水防控警戒压力有所降低；中国西南地区东部至东北东部一线铁路出巡风险时数明显增多，西南地区东部限速和封锁风险时数明显增多，铁路降水防控警戒压力有所增加，其中成都路局降水防控警戒压力增加最显著。

Complex topography along with unevenly distributed precipitation and changes in climate pattern make mountainous regions railway in China vulnerable to water-related geological hazards and rainfall-induced floods. This study investigates the impact of global warming on the safe operation of railways by analyzing the spatial and temporal variations of precipitation, changes in precipitation level distributions, and variations in the threshold hours for rainfall alert levels. The findings are as follows: (1) In recent years, there has been a significant decrease in annual precipitation in southern Jiangnan and south China, while there has been a significant increase in precipitation in the eastern parts of northwest and the northeastern parts of southwest. Management Areas of Guangzhou, Nanchang and Nanning Railway Bureaus have the highest annual precipitation which shows a decreasing trend, while areas of Zhengzhou, Jinan, and Xi'an Bureaus show an increasing trend in annual precipitation. The strong East Asian summer monsoon and the northward shift of the subtropical high are the main causes of precipitation changes. (2) Shenyang Bureau shows the most significant increase in precipitation intensity, while Nanning Bureau shows the most significant decrease. The changes in precipitation intensity are mainly related to variations in typhoons and short-duration heavy rainfall. (3) From the perspective of precipitation level distribution, in the past five years there has been a decrease in the frequency of heavy precipitation occurrence in bureaus such as Urumqi and Lanzhou in the northwest region, while there has been an increase in the frequency of heavy precipitation occurrence in bureaus such as Nanchang and Chengdu in the southwest to Jiangnan region. (4) Guangdong, Hainan, the eastern parts of the southwest region, and the northeastern parts of North China to the southeastern parts of Northeast China are the three high-value areas for railway alert hours due to precipitation. The high-value area for speed restriction hours has narrowed down to the eastern parts of the southwest region, and the high-value area for closure hours has further narrowed down. Overall, under the background of climate change, there has been a significant decrease in precipitation in southern Jiangnan and South China, leading to a reduction in rainfall hours and railway patrol hours, a slight decrease in speed restriction hours, and a decrease in the alert pressure for railway precipitation control. On the other hand, there has been a significant increase in railway patrol hours in the eastern parts of the southwest region to the northeastern parts of Northeast China, with a noticeable increase in speed restriction and closure hours in the eastern parts of the southwest region. This has resulted in an enhancement of alert pressure for railway precipitation control, with Chengdu Bureau showing a significant increase in patrol hours, speed restriction hours, and closure hours.