在双台风判定客观标准的基础上提出影响中国双台风的定义：在双台风活动期间，双台风中至少有一个台风对中国大陆或2个大岛——海南岛和台湾岛之一造成降水的双台风，称为影响中国双台风。然后利用台站逐日降水资料和台风最佳路径资料，采用热带气旋（TC）降水天气图客观识别法（OSAT）和上述定义，对1960—2017年的影响中国双台风进行研究。结果表明：1960—2017年影响中国双台风共有255对，年均4.4对，占西北太平洋双台风总数的60.6%。影响中国双台风年频数表现为显著下降趋势。影响中国双台风的影响期最长可达10天，主要集中在1天、2天和3天，分别占18.8%，29.4%和24.3%。在地理分布上，影响中国双台风主要分布在112°~138°E、12°~30°N范围，频发区在菲律宾北部附近洋面；受双台风影响的年均频次和年均降水均表现为由东南沿海向西北内陆阶梯递减，主要影响区为中国的台湾岛、东南沿海和华南沿海，其中台湾岛受影响最大。进一步分析发现，影响中国双台风影响期内出现单站最大日降水当日两TC平均位置主要表现为东—西向分布，西台风和东台风正好分别位于东亚夏季风的西南风水汽通道和副热带高压西南侧东南风暖湿气流中，不仅有利于西台风从西南风水汽通道中获得水汽，而且有利于东台风向西台风的水汽输送，从而有利于西台风对中国台湾岛、东南沿海和华南沿海造成的强降水。

Based on the definition of Binary Tropical Cyclones (BTCs), the definition of influencing china binary tropical cyclones (ICBTCs) was proposed. During the BTCs period, if at least one of the two tropical cyclones causes precipitation over the mainland or one of the two largest islands-Hainan and Taiwan of China, the BTC is called ICBTC. Then, based on daily precipitation data and the tropical cyclone best track data during 1960-2017, this study analyzed the climatic characteristics of ICBTCs using the Objective Synoptic Analysis Technique (OSAT) and the above definitions. First, a total of 255 pairs of ICBTCs, which accounted for 60.6% of the total number of BTCs over the Western North Pacific, occurred with an annual average of 4.4. Annual frequency of ICBTCs showed a significant decreasing trend during 1960-2017. The longest duration of ICBTCs was 10 days, while durations concentrated in 1 day, 2 days and 3 days, accounting for 18.8%, 29.4% and 24.3%, respectively. In terms of geographical distribution, the ICBTCs mainly occurred over the range of 112°~138°E, 12°~30°N, with frequent zones in the oceans around the northern Philippines. In addition, both annual mean frequency and precipitation of the ICBTCs decrease from the southeast coast areas to the northwest inland regions, with severely-affected areas being the Taiwan Island, the Southeast Coast and the South Coast, and the most-severely-affected area being the Taiwan Island. Further analyses reveal that the average position of the two TCs on the maximum daily precipitation day during the ICBTCs period show an east-west distribution pattern, with the western TCs and the eastern TCs locating in the southwest wind water vapor channel of the East Asian Summer Monsoon and the warm-wet air flow of the southeast-wind on the southwest side of the subtropical high. This situation is beneficial to the western TCs obtaining water vapor from the southwest wind water vapor channel, and to the eastern TCs conveying water vapor to the western TCs, and then as a result, to the heavy rainfall over the Taiwan Island, the Southeast and the South Coasts of China caused by the western TCs.