Variance formula, linear estimation method and non-parametric test method are used to analyze the trend, abrupt change and other characteristics of temperature elements in Hongze region from 1961 to 2020. It is concluded that the distance between the annual mean minimum temperature and the annual mean maximum temperature is the closest, and the distance between the annual mean maximum temperature and the annual mean temperature is the farthest. The annual mean temperature fluctuates. The seasonal average temperature also fluctuated significantly. The average temperature fluctuated and increased in spring, decreased first and then increased in summer, changed gently in autumn, and changed the most in winter. The inter-annual variation of the annual temperature difference was obvious. There was a sudden change in the annual mean temperature in 1994.