Abstract: Oil shale in-situ heat injection technology is very competitive to exploit oil shale. The deformation of oil shale with heat will affect the migration pathway of thermolysis products and stability of heat-injection well and production well. Utilizing the self-developed high temperature triaxial rock mechanics test system, the law of axial deformation with temperature under the stress condition of 500m was studied.The results indicate that:1)The overall deformation of oil shale is dilated from room temperature(RT) to 600℃.The dilation deformation can be divided into two stages: low temperature expansion from RT to 300 ℃ and high temperature expansion between 300℃ and 600℃. The coefficient of linear thermal expansion in high temperatures is larger than that of the low temperature stage;2) Organic pyrolysis has little impact on thermal deformation of oil shale with less organic matter, but has significant impact on coal rich in organic matter;3) In the process of heat injection to exploit shale oil and gas, the thermal expansion of oil shale layer and roof strata may lead to slight surface uplift, which is different from the surface collapse in traditional mining.