To further improve the calculation accuracy of farmland evapotranspiration and irrigation, and to optimize agricultural irrigation water resources allocation, the spatial and temporal distribution characteristics of the crop coefficients of winter wheat, summer maize and cotton in Hebei Province are analyzed using the segment single value averaged crop coefficient method based on the daily meteorological data from 1955 to 2014 in Hebei Province. The results show that from 1955 to 2014, the coefficients of winter wheat, summer maize and cotton crop has a non-significant downward trend, and the average crop coefficients during the whole growth period are 0. 86, 0. 85 and 0. 83, respectively. In different periods of birth, the coefficient for winter wheat, summer maize and cotton crop are in the variation interval of ［0. 40, 1. 29］, ［0. 49, 1. 24］ and ［0. 30, 1. 29］, respectively. In the whole growth period, the crop coefficients of both winter wheat and summer maize show an increasing trend at Xingtai as the center. The cotton crop coefficient increases gradually from west to east with unobvious spatial differences. In different growth periods, the crop coefficient in most reproductive periods of wheat and cotton gradually increase from west to east, but the crop coefficient of summer maize gradually increases from Xingtai to all round. The decrease of wind speed and sunshine duration are the main reasons for the decrease of crop coefficient.