The sunflower growing region in northern China is mainly located in arid and semi-arid areas, and the yield is governed by wet and dry conditions. The non-homogeneous variation of water resources between different regions in the context of climate change has increased uncertainty of sunflower production. Based on daily meteorological data from 296 stations in the sunflower growing region in northern China, the wetness index and standardized precipitation evapotranspiration index (SPEI) calculated on the basis of precipitation and crop evapotranspiration are used to analyze the spatial and temporal characteristics of dry and wet conditions and the influence of major meteorological factors on crop evapotranspiration in the sunflower growing season from 1961 to 2020, and the causes of changes in dry and wet conditions are explored by using sensitivity and contribution rate method. The results show that the frequency of drought in sunflower growing season in northern China generally presented a spatial distribution decreasing from west to east, among which the frequency of drought was higher in northern Xinjiang, northern Ningxia and western Inner Mongolia. In the last 60 years, both precipitation and evapotranspiration in sunflower growing season decreased. The SPEI had an abrupt change in 1980, and compared with the period of 1961-1980, the frequency of slight, medium and severe drought during 1981-2020 generally decreased by 5.63%, 4.41%, 2.49%. Obvious differences between different regions in terms of dry and wet conditions were found, with the climate in Chifeng of Inner Mongolia, southern Liaoning and the North China plain showing a warm and dry trend, and the climate in western Inner Mongolia and Xinjiang becoming wet. The change in temperature and relative humidity increased crop evapotranspiration, but the change in sunshine hours and wind speed decreased crop evapotranspiration in the last 60 years in sunflower growing season. The contribution rate of wind speed and sunshine hours at 55.39% stations to crop evapotranspiration is greater than that of temperature, resulting in a significant decrease of crop evapotranspiration.