Objective To obtain the Young's modulus of graphite in high-temperature environment, and provide reliable technical guarantee for the design of aircraft thermal protection systems and high-temperature structure.Methods Combining the digital image correlation (DIC) method and energized resistance heating technology, this paper established a test system for measuring mechanical properties in high-temperature environment. Using this system, this paper obtained the surface strain field and stress-strain curve of graphite at different temperatures, and calculated Young's modulus of graphite in high-temperature en-vironment. The tensile strain data of Ultra High Temperature Ceramic specimens were measured using DIC and high tempera- ture extensometer method simultaneously at 1400℃ in the experimental environment, and comparison and verification were conducted.Results The strain-time curves of UHTC measured by DIC and high-temperature extensometer method at 1400℃ in the experimental environment were in good agreement, with a variance of 1.3×10-7. In high-temperature environments with temperatures of 1200 ~ 1900℃, the Young's modulus of graphite increased linearly with the increase of temperature.Conclu-sions The method based on DIC was accurate and effective, and this method could easily and quickly achieve the measurement of the Young's modulus of graphite material in high-temperature environment. Moreover, the method could also be applied to measure the Young's modulus of other conductive materials.%目的：为了得到石墨在高温环境下的杨氏模量，为飞行器热防护系统和高温热结构的设计提供可靠的技术保障。方法基于数字图像相关（DIC）方法和通电电阻加热技术，建立一套测量材料在高温环境下力学性能的测试系统。利用该系统，测量高温下石墨试样的表面应变场和应力-应变曲线，计算相应温度下的杨氏模量。在1400℃实验环境下，采用基于DIC与高温引伸计的方法同时测量超高温陶瓷试件的拉伸应变数据，并进行比较验证。结果在1400℃实验环境下，采用基于 DIC 与高温引伸计方法测得超高温陶瓷的应变-时间曲线吻合良好，方差为1.3×10-7。1200~1900℃高温环境下，石墨的杨氏模量随温度的升高呈线性增长趋势。结论采用基于DIC方法准确有效，该方法可方便快速地实现对石墨材料在高温环境下杨氏模量的测量。另外，该方法也可应用于其他导电材料杨氏模量的测试。
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