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Based on the influence of temperature on the growth and development of walnut from germination to young fruit stage, the membership function for the suitability model of daily average temperature is established. The daily minimum temperature, lethal temperature, disaster-causing temperature and the duration below the disaster-causing temperature were introduced into the temperature membership function, and the membership function for the suitability model of daily minimum temperature is established. According to a certain weight combination, the membership function for the suitability model of temperature from germination to young fruit stage of walnut in Taihang mountain area of Hebei Province is constructed. The calculation and analysis based on the model show that when freezing injury occurs, the daily average temperature suitability is generally below 0.8, and the daily minimum temperature suitability and comprehensive temperature suitability are generally below 0.6. The grade of freezing injury is divided according to the value of comprehensive suitability of temperature (S): 0.5<S≤0.6, slight freezing injury; 0.4<S≤0.5, mild freezing injury; 0.1<S≤0.4, moderate freezing injury; S≤0.1, severe freezing injury. Combined with many years of investigation and historical meteorological data, the accuracy of determining the frost damage level based on the comprehensive temperature suitability is 84%. The suitability model better reflects the influence of temperature on the suitability of walnut growth. Combined with the application of intelligent grid numerical prediction, the model will provide some services reference for early warning on freezing injury monitoring in the forest and fruit industry.