Abstract: A device for a low stress triaxial test includes a test platform; a pressure chamber disposed on the test platform; a base disposed on the pressure chamber and fixed to the test platform; a support disposed on the test platform; a servo motor disposed on the support; a loading piston connected to the servo motor and penetrating into the pressure chamber; an axial force sensor disposed on the loading piston; a top cap detachably connected to the loading piston and covering the sample; a first pipeline connected to the base and passing through the test platform to connect with a measurement system; a second pipeline connected to the pressure chamber and passing through the test platform to connect with a confining pressure control system; and a third pipeline connected to the first pipeline and the top cap. The device can ensure the accuracy and authenticity of test results.