为了研究高温对细砂岩力学性质的影响，对经历400 ℃～1 000 ℃高温后细砂岩试样进行X衍射、电镜扫描及单轴压缩试验，分析了高温后试样矿物成分、结构特征及力学参数与温度的相关性。结果表明：高温后细砂岩试样内矿物发生了多晶转变，经历600 ℃以内高温试样内石英含量随温度升高增加，晶体衍射强度增强，600 ℃高温试样可观察到明显熔融和重结晶现象，超过600 ℃高温后试样内石英含量随温度升高降低，晶体衍射强度减弱，裂隙数量增多，裂隙宽度和长度有所增加，裂隙可分沿颗粒边界裂隙和穿过颗粒裂隙，600 ℃约为主要矿物石英变晶的临界温度；经历400 ℃～800 ℃高温后试样的纵波波速与温度呈线性降低；经历600 ℃以内高温对试样的强度具有强化作用，超过600 ℃高温后试样强度开始弱化，600 ℃可作为试样强弱转化的阈值温度；经历400 ℃高温后试样弹性模量、变形模量随温度升高稍有增加，初始模量和峰值应变基本保持不变。超过600 ℃高温后试样的变形参数随温度升高有所降低，超过400 ℃高温后峰值应变随温度升高单调增加，高温对细砂岩试样变形参数的影响较为敏感。

To investigate mechanical parameters of fine-grained sandstone after high temperature, X-ray diffraction, scanning electron microscope (SEM) and uniaxial compression tests are conducted on fine-grained sandstone samples after 400~1 000 ℃ heating treatment. The correlation among mineral composition, structure characteristics and mechanical parameters of samples and temperatures is analyzed. The results show that: the polycrystalline occours in the fine-grained sandstone after high temperature treatments. Within 600 ℃, quartz content in the sample increases with increasing temperature, crystal diffraction enhances, and melting and recrystallization phenomenon can be observed clearly when the temperature is 600 ℃. Above 600 ℃, quartz content reduces with increasing temperature, the intensity of crystal diffraction is weakened, the crack quantity, the width and length increase, and cracks can be divided into the crack through the particles and along the grain boundary. The temperature of 600 ℃ is the critical temperature of quartz crystalloblast approximately. Within the range of 400 ℃ to 800 ℃, longitudinal wave velocity of the sample linearly decreases with the temperature. The sample strength is strengthened under 600 ℃, but the sample strength is weakened over 600 ℃. Thus, 600 ℃ can be used as a threshold temperature of strength conversion of samples. Within 400 ℃, elastic modulus and deformation modulus of samples increase slightly with the temperature increasing, and initial modulus and peak strain remain basically. However, deformation parameters of samples decrease with the temperature increasing above 600 ℃, and peak strain increases monotonically with temperature increasing above 400 ℃. The deformation parameters of fine-grained sandstone samples are more sensitive to the high temperature.