The utility model discloses a testable rock coefficient of heat conductivity's true triaxial test device, including 1 direction loading system of sigma, 2 direction loading system of sigma, 3 direction loading system of sigma, 1 direction loading system of sigma includes the vertical force piston, goes up the pressure head, 2 direction loading system of sigma include that the pump moves loading part, manual loading part, 3 direction loading system of sigma include oil pipeline, the vertical force piston set up in directly over going up the pressure head, be provided with on the rock sample upward pressure head, lower extreme are provided with the base, control both ends and be provided with horizontal pressure head respectively, oil pipeline and hydraulic pressure servopump are connected. The shortcoming that current rock mechanics test separately goes on, rock coefficient of heat conductivity's conventional triaxial test device can not accurately react the coefficient of heat conductivity of rock under true load -bearing state has been overcome with coefficient of heat conductivity's test, have rational in infrastructure, processing ease, advantage that the precision is high.