The invention provides a solid expansion demonstrator, which comprises a support, a laser pointer group which is formed by two or more laser pointers, a liquid container which can store heat sources, a plate for positioning an experience rod of solid to be measured, and a device for adjusting the experience rod of the solid to be measured, wherein an operating platform of the support is in a shape of a Chinese character 'ao'; a plane at the bottom of the operating platform is provided with a plurality of holes; a plurality of 'U'-shaped grooves are arranged on ribs on both sides of the operating platform; the laser pointers are fixed inside the 'U'-shaped grooves; the plate for positioning the experience rod of the solid to be measured is arranged inside the container and positions the experience rod of the solid to be measured; the experience rod of the solid to be measured passes through the holes of the operating platform of the support, is vertically arranged inside the container and adjusted by the adjusting device, and closely contacts the laser pointers without extrusion; and a reference laser pointer in the laser pointer group is immobilized, and residual laser pointers can perform friction-free rotation.