To deeply understand the probability of typhoon disasters in Yangtze River Delta, the years with severe typhoon disasters based on the number of influenced counties during 1644-1949 were sorted. Results show that 38 counties were struck by typhoon in 1696 and the typhoon frequency is the only once in 300 years. The second and third are in 1724 and 1781, the typhoon frequencies are once in 100-300 years. And in 1732,1747,1877, the frequencies are once in 50-100 years. In 1696 and 1732, the disastrous areas were mostly distributed in the Yangtze River Estuary, while they were distributed in the Yangtze River Estuary and the Hangzhou Bay in 1724, 1747 and 1781, and mainly concentrated on the south of the Yangtze River and the north of the Hangzhou Bay in 1877. Both of the two disasters in 1696 landed near Shanghai, heavy rains and storm surge of the first disaster and storm surge of the second disaster caused floods. In 1724, the typhoon landed near Fengxian county of Shanghai, heavy rains and storm surge caused disasters. The typhoon in 1781 landed near Jiashan county, the main disaster-causing factor was storm surge. In 1732, the landfalling location was near the south of Yangtze River Estuary, both of heavy rains and storm surge leaded to floods. The typhoon in 1747 landed near Baoshan county and Chongming county, the disaster was mainly caused by storm surge. The typhoon in 1877 landed near Taicang, Baoshan and Jiading county, the main disaster-causing factors were strong wind and heavy rains.