A crystal growth apparatus includes a crucible, a heating device, a thermal insulation cover, and a driving device. The crucible contains materials to be melted, wherein the heating device heats the crucible to melt the materials; the thermal insulation cover is provided upon the materials, wherein the thermal insulation cover includes a main body, which has a bottom surface facing an interior of the crucible, and a insulating member being provided at the main body; the driving device moves the thermal insulation cover towards or away from the materials, whereby, the thermal insulation cover effectively blocks heat conduction and heat convection, which prevents thermal energy from escaping out of the crucible.