Based on the tropical cyclone data of the Joint Typhoon Warning Center (JTWC), this study explores the spatial and temporal variation characteristics of tropical cyclone activity in China during the 70 years from 1951 to 2020, and the possible spatial and temporal variation mechanism of ENSO on landing tropical cyclone activity. The main conclusions are as follows: (1) the tropical Accumulated Cyclone Energy index (ACE) in China has obvious characteristics of inter-annual and chronological changes. From the long-term change trend, the cyclone energy index is significantly weakened. (2) No significant correlation was found between the cyclone energy index and the sea surface temperature in the Niño 3.4 zone. The correlation coefficient of the cyclone energy index and the sea surface temperature in ENSO 3.4 area was positive from 1951 to the late 1990s, negative from the early 2000s to 2020, and mutations occurred around 1967 and 1994. (3) The area with high observation intensity is located in the southeast area of Taiwan Island (120–130°E, 15–25°N), and the second high value area is the South China Sea (110–115°E, 15–20°N). The spatial distribution of the first eigenvector of the observed intensity EOF is essentially the same as that for many years. The time coefficient of the first mode changed twice in 1972 and 1982, indicating that the trend weakened after 1972, and the trend strengthened rapidly by 1982. The spatial distribution of the second eigenvector is mainly found in the northwest Pacific Ocean (130–140°E, 15–25°N) region, and the negative center is mainly distributed near the archipelago of the Philippine group (120–130°E, 10–20°N), showing a positive-negative spatial distribution feature. The time coefficient of the second mode indicates that such spatial distribution features often show opposite trends, and the time coefficient is mutated around 1977, indicating that the opposite trend of observed intensity began to weaken in the late 1977s. In the year of ElNiño, the observation intensity in the south China coast of South China and the northeastern part of the Japanese Sea of the Philippines was increasing, with the decrease mainly distributed in the Bohai Sea, Yellow Sea, East China Sea, the Korean Peninsula and the eastern and western waters of the Philippines. In the year of LaNiña, the observation intensity of coastal areas in China decreased, while the trend of observation intensity increased in the Philippines.